A pill bottle for a keychain that will hold 3 - 4 8mm or so diameter pills. Designed for a co-worker that is allergic to bees and has to carry some pills around.
Updated 5/28/14 - I added an stl for a gasket I made out of flexible filament.
This was one of my first tries with Openscad. You will need the "Thread Library.scad" from http://www.thingiverse.com/thing:8793
Print out the three pieces (cylinder body, cap and hook). Glue the hook into the cap with acetone / abs glue (dissolved abs and acetone).
Screw the cap onto the pill bottle then unscrew and screw it back on a few times to loosen it. If needed you can add a dab of silicone or cooking oil on the threads.
Possible improvements: Use http://www.thingiverse.com/thing:9095 to put on a knurled finish on the cap. I saw this library after I had made mine and put groves in my way.
I printed at 100% fill .25mm layers on a Makerbot TOM w/MK7
*update 5/28/14 - I added an stl for a gasket I made out of flexible filament. It worked well.