The most common problem on the iphone 4S which has been exposed to water is battery failure. With the 3GS it is usually the LCD. Remember that the rice trick is only a temporary solution since moisture can still be trapped inside of the main board shielding. Read more about what to do with a wet cell phone here. As a previous poster said, turning the phone on is a bad idea as it causes electricity to flow through components that are still wet. This can easily short something out and cause more damage. Once you replace the battery pay attention to whether the phone gets hot while charging. This is a good sign that you will have problems in the future.
Have you tried bypassing the "ipad is disabled" screen? There is an easy way to do it with the first ipad and I have heard that it now works with the ipad 2 by selecting ipad from the drop down menu in Gecko. The instructions can be found here.
So you had a PUK code on your SIM? If that's the case try a different SIM and see if you can call out. Does your phone show signal strength? No service? Searching? More information would be helpful. Recover your iPhone pass code