What companies will fix a water damaged iPhone 4?

The other day I found an abandoned iPhone 4 in the middle of the street. It was covered in what I think was beer and it had just rained but not a lot. I peeled off the cover and the iPhone from there wasn't so damaged or wet. I rubbed it with a moist towel and some Windex and put it in a bowl of rice since it's supposed to help with water damage. But, if that doesn't help, does anyone know of any stores in the Placentia, Brea, Yorba Linda, Fullerton area where I can drop it off to get fixed for a cheap price. Well anything under $50 is okay but I'm kind of looking for somewhere under $20 or $30. Thanx to everyone!!!