Stuck in a dorm room or tiny apartment, but still want to play guitar? DIY site Make shows you how to build a tiny little practice amp inside a box of biscuits for around $US30 (cheaper if you have the parts already).
You don't need much to build this little amp and it should only take around an hour to build the whole thing. It's not going to sound outstanding or anything, but for $US30 it's a fun way to make your own amp and learn a bit about electronics along the way.
The $US5 Cracker Box Amp [Make]