Futaba has released an interesting new type of servo.
Its non-continuous, and you can't modify it to rotate continuously.
However, you can manually rotate it continuously forever - making you think it was continuous but not really. It has no mechanical stop, yet still acts like it does when you power it up.
I've only played around with it a little, but I see this as a good thing as the mechanical stops on my Hitec servos keep breaking. Replacement case sets are like $8 . . .
This is the one I have:http://www.servocity.com/html/s3156_servo.html