We got a "Go Dog Go" that is similar to this contraption http://www.buygodoggo.com/ . Unfortunately our incessant ball dog (German Shepherd-like thing) won't drop it into the bucket! I don't think he trusts it.
This one looks good for 'dem smaller in stature dogs!
You guys haven't done this much, have ya? I suggest you study this tiny ad:
Large Lot for Sale Inside an Established Permaculture Community — Bejuco, Costa Rica