Check out this great KeyTool from ThinkGeek that fits over one of the existing keys in your keychain so it doesn’t take up any more space.
It includes:
* Large screwdriver
* Medium screwdriver
* Small screwdriver
* Nail file
* Finger nail cleaner
* Bottle cap opener
* Wire cutter
* Tweezers
Sadly it’s out of stock right now.
Seen on Uncrate