a battery box for AA batteries. designed to be see-through. i usually put empty batteries upside down into the box, so it's important to see the batteries from the outside. also, it uses significantly less material than other boxes, making it way faster to print.
the lid stays on the box only by the magic of friction, so your milage may vary if your printer has other tolerances than the one i can use.
the overhang in the top portion is a little on the risky side, but nothing that can't be fixed with a sharp knife in a minute.
ps: if you want to store AAA batteries in this box, use http://www.thingiverse.com/thing:84337 :)
edit: i made a version 2 with chamfered edges that also has something like a groove through the middle to help secure rubber bands.