One of the possible problems with pet ownership is ensuring they have a constant supply of water, and are trained to return to the water bowl when thirsty. The team at AVBrand have solved the water supply problem with an Arduino-controlled water pump and valve system. Not only does it simply fill the dish, it waits until it is truly empty before refilling, to minimise the growth of bacteria due to still water. You can see it in action here:
Another problem solved with an Arduino and some imagination. Now to train the dog! In the meanwhile, to make your own follow the instructions here. To get started with your own Arduino-embedded projects, consider using the Freetronics LeoStick - one of the smallest Arduino-compatibles on the market with onboard USB, RGB LED and piezo: