Ever since I got a dog, and realized said dog would fetch himself to death given the opportunity, I have threatened to build him an automatic ball thrower. Unfortunately, I have the mechanical skills of a chinchilla. Fortunately, someone else has done all the hard work for me:
The Automatic Canine Fetch Machine (catchy name!)
This is great for those people who want a dog, but don't want to have to actually interact with the dog. It's like getting a television for your toddler.
Even a cold, soulless ball throwing mechanotron bucket can't say no to these eyes: