USB to Single Servo board:

This costs less than 40 bucks and has API support for Windows, MacOS X, Linux, and WinCE and language support for Java, C/C, Flash and some scripting languages (through the community). Way cool.

I’ve used a few different Phidget products ( plugging in to the also way-cool Gumstix ) including some RFID kits. They have all been extremely high quality. I wish I had a real project that used them…

Here’s the link to the Single Servo Controller Board