I found this project on Make for an automatic ball thrower for your dog, and am in the process of wrapping it up.
For power, I'm using a cordless drill battery. (Specifically, a Ryobi lithium one+ 18v battery)
I've seen a lot of projects out on the web where people just use electrical tape to wrap the leads of their wire to the battery, but this seems a bit ghetto to me.
In all of the tools, the batteries "snap" into place. Is there some kind of battery mount that snaps a cordless drill battery into place and provides some leads to solder wires to? My google-fu just results in how to rebuild a cordless drill battery, which is NOT what I am looking to do.