I once used a self water dish that was like an upside-down drinking fountain. I filled the reservoir (held about 2 quarts) and flipped it upside down onto the bowl. The water was gravity fed into the bowl. I used this for quite a while, but decided in time that the water must get contaminated when the cat drinks from the bowl (back wash). Molly never got sick, but I worried about her health.
The second self water bowl was the fountain type that Sicycatlinked to. I didn't care for mine (actually the cats didn't care for it). I bought the last one at Wal-Mart on my vet's recommendation(they stopped carrying them). I really wanted a table fountain (the kind with rocks). . . . . but they are getting harder to find.
I'm back to using a glass bowl!!