Saw this pop up on HaD today, thought it might be of use to someone. Sure, you can do the same with an arduino, but if you want to control some servos directly from the computer, this is the key.
Sure, you can buy the same thing for ~$20 or less, but why not build your own! And for probably about $5-6 in components, the price is right.
So, open source USB 6-servo controller based on an ATMEGA8. Enjoy.
http://www.societyofrobots.com/member_tutorials/node/25