iPhone 3Gs got dropped in water. Is it pretty much done?
When this happens don't turn the device on or try to sync it right away. Instead, remove the battery (if possible) and put the device into a sealed bowl that's half full of uncooked rice, crystal cat litter (make sure it's pure crystal) or the desiccant crystals often sold in garden centers. These will all draw the moisture from the device and absorb it. 

Leave the device in the sealed bowl for at least 24 hours. 48 is better, but you might want to check/change the rice after 24. No need to bury the device either--just rest it on top or suspend it on a block of wood, a couple of dowels, or whatever else you can one up with. After 48 hours inspect the device.  If you think it's dry go ahead and test it. 

No guarantees, but with luck you'll be pleasantly surprised.