These are pretty inexpensive to make, and you can put them together in about half an hour if you've made jewelry before. But be warned, it's kind of a loosey goosey process, so you might need to try a few different configurations until you're happy--the final product for this Instructable were my third try!
Step 1: Supplies
Here's what you'll need:
Watch gears (try Ebay--I got a little tin of about 50 gears for $12)
Earring hardware: ear wires, posts, jump rings
Tools: assorted jewelry pliers, wire clips