|Picture by Patrick Hoesly.|
Let us consider the case of a smartphone (Galaxy S) being dipped in clean drinkable water.
First of all: read the picture on the right.
As soon as the bath is over take the device apart (battery, main body, back cover, memory card, SIM card) and dry it wth towel/napkin. Don't shake it, but turn it around to get the water out of holes such as the earphone and USB sockets. Then let it dry for at least 48 hours. Be patient: you aim to recover your data from the device, don't you? This should be your first target. If your device works afterwards then it is luck or well designed technology. Or a combination of both.
I dried mine in a bowl filled with (uncooked!) rice close to a heat radiator. Temperature should have peaked to more than 40°C, but heat is not a must: leave it longer.
When you are ready plug the battery and keep your fingers crossed. If the device powers up be prepared to extract your data using the standard method.
Some online resources mention water-sensitive labels all around these expensive mobile devices. I haven't been able to spot them on the external body of the i9000. Anyway do not lie to the customer service if you are going to return it.
If your device allows to use an external memory card, it is probably wise to save your mobile-authored data on it, or take periodic backups. It is more unlikely that a self-contained hole-less memory card becomes damaged with water (anyway let it equally dry).