Hi,
Here are two libraries, the first will get you 20 servos from 4 pins, the second will drive a servo from every Arduino UNO pin upto 18 Servos.
The interface to this one is ugly, but the philosophy is - if you asked me to do something you had a good reason. The ugly part is that it does not enforce a fixed refresh rate and so if you so not set one it will pulse your servos at much higher frequencies - some people want this ability -
If your interested in using either of them let me know, they are well tested, I consider them reliable but they could be better documented.
Here is the second library in action with some PPM reading code also included in the library -
Duane B
rcarduino.blogspot.com