Name:
Memory Cards for Teleporters
Description:
The coordinates should be stored on some kind of memory card.
One would have to insert it into the teleporter with a right click, then a dialogue would pop up with a list of already visited locations and the ability to save one’s current one.
On selection of one (and maybe confirming, but I think that would be rather annoying on the long term and unusual in MC), one would get teleported to that one.
(Maybe add some kind of seldom failure, where one would be split into two halves or something like that? 
)
My general opinion on teleporters:
Teleporters should teleport the player, teleporting the player and a small room would also be nice (so one would have to build a teleporting chamber or something like that),
but only teleporting the contents of the room without the player wouldn’t be that nice, I think.
Recipe:
I must admit, I actually haven’t thought about one before I startet writing, let’s see …
Maybe use one similar to the one for the programs of the terraformers?
Since they can save “Terrabytes” of files, it should be no problem for them to save a few coordinates and settings.
How they would be programmed then would rely on what Alblaka thought of to build the teleporter.
This would also be possible, for example:
Where: → Tin, → Glowstone, → Gold, → Advanced circuit, → Redstone, → Normal circuit
But, after all, this one is up to Alblaka.
Edit:
Oh, Alblaka was faster than me. His way of implementing it is also fine. 
By the way, relays sound like fun (combined with some synchronized HVs – instant charge of an MFSU :D)
Edit2:
Oh, seems like I misunderstood relays. I thought 256 EU were some sort of result of charging it, not the maximum output. Still nice.