MANY THINGS, however, one of the best uses for a bed would be to jump off your roof onto it :) unless its super thin,,, then probably just sleeping -_-
Crying over your masters degree
Pretty much anything: dozing, talking, sex, reading, writing, thinking, punching bag, cuddly warmth, protection on a bad day, laundry folding table, trampoline, stage, etc etc...
A bed can be used to relaxing, reading a book, playing a handheld game, listening to music, using a laptop, sitting on it and for a friend and you to hang out on. Or to have sex