A bit difficult to drop apple or apple juice or apple sauce from leaves if the main drop is saplings, since the Macerator only has one output slot. But if you macerated apples themselves, I see where you could get that...
And by the time you have a chainsaw and a macerator I think you'll probably have a better food source than apples, too.
Name: Umm.... leaves in macerator gives saplings?
Description: Ever cut down a tree with a chainsaw? Well I'm sure you have since that's the point. But if you've cleared the leaves with the chainsaw too, you get all these leaf blocks too (and some saplings and whatever else those leaves drop). If you've got plenty of saplings of that kind of tree, you'd probably find some way to dispose of these leaves: toss in lava, recycle them, make plantballs. If you didn't have enough saplings, you might take advantage of a quirk of the chainsaw and keep placing the leaves and chopping them down, since you'll always get the leaves back plus the occasional sapling.
I propose, why not let a machine do the latter process for you? Just throw the leaves in a Macerator, and it will chop up the leaves until it finds and spits out a sapling. It won't find a sapling in every leaf block; rates should be somewhere between 1 in 20 for ordinary chopping / decay and 1 in 2 to prevent energy profit. If I had to pick a number, I would pick 1 sapling in 5 leaves, but that's subject to balancing of course.
Recipe: Leaves > (macerator) > Saplings (between 2 and 20 leaf blocks per sapling, on average)
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On a similar note...
Name: Tall Grass / Shrub / Fern + Macerator = Seeds
Description: A logical extension of the above suggestion, you also get tall grass (etc.) as items from the chainsaw (why? eh idc). So if you can macerate leaves to get saplings, you should be able to macerate tall grass to get seeds. Clearly it would have to be balanced differently since the energy considerations are different; it could go as high as 1:1 I suppose. Though I guess it's not terribly useful, it is quite logical.
Recipe: Tall Grass > (macerator) > Seeds (at some percentage chance, possibly as high as 1:1)
Ok so while full Nanosuit gives full immunity from fall damage, that's just because it's 100% armor (above full diamond's 80%, i think) and plain armor doesn't do anything against lava.
Ok got it. Thread closed. (makes sure to always carry that bucket of water near bedrock)
Just a quick question: If you wear full Nanosuit, can you swim (not take damage) from Lava? I don't want to risk my suit on my Survival map, and I can't see if i'm getting damaged much less put on the armor on a new Creative map for testing, so just seeing if anybody may have discovered by accident.
I can see your secret on the left. You use buildcraft, the number one way to get lots of resources without it feeling like cheating (aka not EE). I use it too! 
As another note, I'm going to be going a similar thing, using solar panels to power a mass fab.
Those new suggestion sounds better ... Alternative foods for Dogs/Cats ? I'm for.
+1
And the macerating gives a higher yield... which is what the macerator is for in the first place, and eases the tedium of fishing because you know you'll get more benefit for each fish caught!
2 new suggestions added, Catnip and Pet Food.
I suppose an equally valid idea would be if plantballs could be burned as a fuel item for 1/4th the effectiveness of charcoal, or could be "smelted" or "cooked" in a furnace into such an item, it would still be good since we still have an eight-fold volume reduction from burning reeds directly. But that's not as good as the thirty-two fold reduction as I originally suggested.
Edited the original post to contain this alternative idea.
first fishing is actually one of the fastest and sustainable ways to get food in minecraft you'd have to bone meal wheat to get food from a cold start any faster
second all automatic fishing machines basically turn into massfabs that only make fish
as for farming instead of mutant plants how about a koi pond?
I don't want the fish to eat, that's what my 45x45 one-click-harvest wheat farm is for. I want the fish for cats, who don't eat bread or indeed any other kind of meat for that matter. I suppose if we could lure them with canned food / macerated fish/meat....
I suppose since the intent is to catch and breed cats, if a catnip crop was made and catnip could be used to tame and breed cats, that would be good. But you'd have to keep the cats out of the garden where it's growing. Mwrowr!
And even if the ideas had been denied earlier, before 1.2, with the advent of jungles and cats there's new demand for fish and perhaps there's a chance the idea will be revisited.
I've been trying to fish so I can get cats and post them around the outside of my base to ward off creepers, but fishing is very slow and tedious. Perhaps there could be some more efficient way to get fish? I have a few possibilities:
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Name: Automatic Fisher
Description: Machine that when placed adjacent to a body of water and given power will over time catch fish, probably through a net system or sucking them in through pipes or something. Will work slower with very small bodies of water; needs a certain size to work at maximum speed.
Recipe: No idea except it should be rather basic - possibly wood instead of based off a machine block.
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Name: Iron Fishing Pole and Electric Fishing Pole
Description: The Iron Fishing Pole has a recipe much like the ordinary fishing pole except it uses iron bars instead of sticks. Lasts longer and possibly fishes faster. The electric fishing pole is crafted like many electric tools, with a battery, circuit, and Iron Fishing Pole; it uses energy instead of durability, and possibly fishes even faster.
Recipe: Iron Fishing Pole: Three iron bars in a diagonal with two string on the side, like a fishing rod. Electric Fishing Pole: Battery, Circuit, Iron Fishing Pole in an / shape.
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Name: Fish Plant (?!)
Description: It's a crop that gives Raw Fish when harvested. 
Recipe: Breed random stuff together or something.
======= Some additional ideas:
Name: Catnip
Description: New crop that produces catnip, an item that can tame ocelots and make cats breed just like raw fish. Can also lure ocelots and cats more effectively than fish (maybe not if that's hard to code), and if placed on the ground also acts as a cat/ocelot lure.
Recipe: Proposed breeding product of hops and some sort of flower. Hops for flavor and flowers for scent.
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Name: Pet Food / Dog Food / Cat Food
Description: Macerated meat or fish will become 2 Pet Food, which can tame/breed both Wolves and Cats. Alternatively, only macerated Raw Fish can turn into Cat Food which only works on cats, and any other sort of macerated meat will become Dog Food which only works on Wolves. Probably only raw meat/fish should work, and rotten meat only yields one instead of two because it's so abundant.
Recipe: In Macerator: Raw Fish > 2 Cat Food / Pet Food, Raw Chicken/Raw Beef/Raw Pork > 2 Dog Food / Pet Food, Rotten Meat > 1 Dog Food / Pet Food
Add some kind of Water/LavaPack for the hand pump, and I would give you a cookie sir.
I suppose it could be adapted for lava, but it couldn't carry both at the same time or you'll have some chiseling to do!
Another satisfactory way would be to craft one empty cell above one "treetap" (really it's a spigot) and voila you have a cell that can place as well as pick up water. Lava? Well the spigot is wood, but we could handwave that away.
I suppose another way I could dispose of leaf blocks would be to build a line of them on a wall then set them on fire. Since fire destroying leaves also drops saplings, I get my saplings as they drop to safety, and I get rid of my leaves.
...yeah rubber and birch use the same leaves to save on block id's try breeding sticky reed
you can use the custom recipes mod to add a recipe that lets you craft leaves into plant balls
Ah good I'll start repairing. I'll get to agriculture... eventually...
Leaves can already be crafted into plantballs. I just can't use the plantballs on anything useful without using up nonrenewable tin. 
Display Moreyou can do the following to manage your leaves/clear your inentory
1. plant all trees on a 1x1 dirt block so you can get underneath with out knocking off leaves(then they will decay on their own)
2. lay and punch like gravel
3. throw the leaves on the ground/in a deep hole and wait for them to despawn
4. install a mod that uses leaf blocks
5. make and maintain hedge statues and other decorations around your house(i recommend a series of hedge lined cobble road with stone slab side walks leading every where)
6. use it as guilt free recycler fodder (you know you feel guilty building that cobble gen just to make scrap admit it)
7. throw it in lava (you already have lava laying around from your cobble gen just convert it to a disposal)
8. use the chainsaw as a weapon to gain exp and enchant yourself a diamond axe
9. throw it in an EE transmutation table
1: I plant birches so I don't have to worry. And this doesn't apply to wild trees I have to clear. And breaking with a chainsaw is faster than decay.
2: Annoying to have to forgo the benefits of industrialization, but reasonable.
3: Well I like at least breaking even on saplings for replanting, though if they drop when I break with the chainsaw in the first place that's ok.
4: I'm happy with IC2 and Buildcraft.
5: Interesting idea! Maybe a hedge maze.
6: Probably what I'm going to do.
7: See 3.
8: Or the nanosaber. Never have done enchanting since I have IC2, might if there's an "unbreakable" enchant and I have enough diamonds to spare. But then again, would it be as fast as the chainsaw?
9: I assume that's from some mod. See 4.
And I will note that this does *not* happen with rubber trees, darn it. Would have made making a rubber plantation so easy, had to do it the hard way. Birch and rubber trees have leaves that look the same, right? Maybe I can patch some of my rubber trees with birch leaves, they got kinda ripped up when I was chopping down their neighbors.
I suppose an equally valid idea would be if plantballs could be burned as a fuel item for 1/4th the effectiveness of charcoal, or could be "smelted" or "cooked" in a furnace into such an item, it would still be good since we still have an eight-fold volume reduction from burning reeds directly. But that's not as good as the thirty-two fold reduction as I originally suggested.
So I've got perpetual leaf blocks that I can reharvest over and over completely unlike gravel which drops gravel OR flint, not both. And since I keep chopping down trees for wood, I'll keep getting more of these perpetual leaf blocks. What can I use them up on? I can't burn them as fuel like I can reeds or cactus or saplings. I could make plantballs, but their only use is biofuel which uses up tin to make energy, which I won't do because why would I use up nonrenewable resources on renewable energy?
I suppose if leaves could be burned like reeds (aka not for very much) and/or plantballs could be made into a less efficient but less bulky and more renewable fuel (read: http://forum.industrial-craft.…?page=Thread&postID=58517 ) this wouldn't be so bad. But as of now I have to place down all the leaf blocks I harvest and were cluttering my inventory and break them with something else (like a torch), or run them through my recyclers.
I'm pretty sure it's a bug. Electric shears as an item separate from chainsaws are planned to be implemented, yes?
NO! I HAVEN'T MADE MY UNLIMITED APPLE GEN YET! fyi breaking a leaf with a chainsaw drops both leaves, and saplings, and apples. and you can just set a leaf block down and hit it over and over if you want.
I just discovered that myself. I am certain that will be nerfed.
I've been using my chainsaw to cut down trees (that's what it's for!) and on ordinary trees (not rubber trees, those work fine) when I use the chainsaw to clear the leaves it gives me leaf blocks - which I do not want! I want to destroy the leaves to get saplings back so I can replant my trees or use the excess for fuel, not get useless leaf blocks, and I want to use my chainsaw because it is much faster at destroying leaf blocks. Will this characteristic be removed in a future version of IC2?
I hear that chainsaws have been made to act like like electric shears as well as an electric axe. I hope this will be replaced with an actual electric shears tool, instead of throwing this on the chainsaw.
