Terraformers should change biomes in chunks, instead of only simulating the biome's effects. Or add some "Permament" Terraformer, that changes the biome until overwritten with a different setting. Also, it would be extremely power-hungry. 
Note: Since 1.2, Chunks store biome data inside, making changing biomes much easier. For example, WorldEdit can change biomes in selection by //setbiome biomename.
Well, since the Mining laser's extreme heat can be used to melt blocks, why can't we use it to kill mobs efficiently? There should be a mode that affects only organic-based things, such as NPCs, Plants, leaves and stuff, but won't damage blocks like stone and glass.
Not a forcefield, more likely a "retractable" bridge, useful against mobs or in Multiplayer. It could be only rotated horizontally.
Some people have loads of energy, but what do with it? MAKE PURE ENERGY BRIDGES! With this fancy Machine, you can create semi-transparent glowing drawbridges made entirely of your easily harvested electricity! Doesn't that sound awesome?
Also... The more energy is flowing into the Machine, the longer the bridge is! So for example, if you connect a LV Cable to it, it's 8 blocks long. But If you hook it up to a HV Cable, it can be even 32 blocks long! But beware, it usually explodes if the amount of energy is too high.
How does it look: (Textures. :D, the dark "laser" field has 60% Alpha)
Today, I've opened my new Alcohol Store, and found out that you can't sell Rum, because every mug has different metadata, making Booze Trading useless. Could this get fixed? It pretty much ruined my work I was doing for almost a week. 
