Wet iPhone 4 doesn't know its IMEI and ICCID and displays connect to iTunes but lacks passcode
I dropped mine into water shortly after buying it and I saw some weird behaviour too.  I figured that it was submerged for such a short time, less than a second, that not much water would have penetrated the case so that maybe the weird behaviour was down to some shorting that was happening in the dock connector and the headphone socket so I made sure these were clean and entirely dry.  I plugged a dock connector in and out lots of times and after a day or so the weird behaviour stopped.  You can also try putting the phone into a bag of rice which will dry out any residual moisture.  You could wrap it lightly in tissue paper to prevent any small pieces of rice from entering the body of the phone.