Grumpy_Mike:
The point about a rotating servo is that you can only control the speed and direction of the motor, you can not set an angle.
Hi,
Yes, and i thought that would be good enough for the application as there have been a lot of ideas kicking around about how to do this (solenoids and motors and such). If not, then i guess he wont be using that 
It did look interesting although i checked out one site and it doesnt look too easy to do with some servos. Maybe better off buying one that has complete rotation if that can work for the application.
Yeah, controlling the angle is where it's at. That helps in a lot of applications.
We once did an electronic weigh scale for weighing lab animal organs after dissection. The scale was very sensitive so it had to be covered when a measurement was being taken, so we used a clear half dome and powered it with a servo. The dome would open and close with a user operated foot switch. It was cool to watch, and it looked like a little alien flying saucer
I wish i had pics of it, but back then i dont think we had any digital cameras yet and nobody thought of taking any pics anyway.