The Gartenmeister Bewässerungs Revolver (Irrigation Revolver) combines my favorite sport (shooting) with my least favorite chore (gardening). This Swiss/German tool features a full automatic design (one trigger pull fires unlimited gallons of water), safety switch, hammer (which adjust the water pressure) and interchangeable nozzles.
At just € 9.99 ($13.80) I think it is a bargain. The only thing better than using this to water the garden would be to not have to water it at all. I have Googled and Googled for a store that exports them but unfortunately found none.
Many thanks to Niels for the tip.