Why a worm farm?--that's one i can answer...a worm farm is an apartment dwellers answer to a compost heap. (unfortunately, it gets too cold in NYC for the worms to winter over) you put your food garbage in, and get worm casting and compost out...

the composted soil+ worm castings is the best stuff you find for your potted plants (so you contain grown tomatoes are rich red and delicous!)