Most people have to keep track of at least a few keys. The easiest way to do that is to just keep them all on one key ring. But the more keys you have, the more they fan out on the ring. If you have a lot of keys, then your key ring can get pretty bulky and impractical to carry in your pocket. Here is an alternate design for holding and organizing your keys that is a little more efficient.
The design of this key holder is very similar in construction to a Swiss Army Knife. The keys are arranged on two parallel bars. Each key can be rotated into the handle for compact storage and rotated back out for use.
Complete instructions can be found at: http://www.instructables.com/id/Swiss-Army-Key-Ring/
See the full series here.