Chech out the Argo Navis at the manufacterers (an Australian company) website.
http://www.wildcard-innovations.com.au/
The AN is an easy to use but powerful tool that can help turn your telescope into a "push to" observing machine.
While the AN alone will not "drive" your scope it can be combined with another system (Servo-cat...maybe others) to convert your dobsonian mounted reflector into a full go to.
I've got two of them and they are fabulous...I highly recommend the Argo Navis.