This instructable will cover two ways that can help you repair a "wet" phone. As water damage varies from case to case, there is no guarantees that this will work in your case, but it is worth a try!

It is important to know that these procedures will NOT void warranty. However, if your phone has been water damaged, there is a large chance your warranty is already void! On newer phones, there is usually a sticker in the battery bay that is used to tell the manufacturer when a phone has been "water damaged" which allows the manufacturer to then cancel the warranty. This sticker is usually round in shape, and starts off white when it is not wet. Although, I think my samsung a900M started with brown and went to black.

If neither of these methods work, and your sticker is still it's original color, try to have your phone serviced under warranty.

CAUTION: Before attempting ANY method in this instructable, remove the battery, battery door, and SIM card if applicable, and place them in a safe location!

DISCLAIMER: I am not responsible for any damages to your phone as a result of you attempting any of these methods, do so at your own risk.

Step 1: Understanding the Problem

When your phone got wet, it most likely got some moisture trapped inside it. This moisture causes the phone to behave very funny, and possibly not even power up.
This is due to the conductivity of water (It's ability to have electrical current pass through it.) This moisture can bridge certain connections in your phone, causing these behaviors.

Even though your phone may behave fine at first, it is better to dry the phone before use anyways, as the water that remains inside can be moved around, and cause issues later.

So what to remember, is that after exposing your phone to moisture, you want to nullify the moisture inside.

Step 2: Prepping the Phone for "repair"

As we discussed in the last step, we want to make the water either dry up, or we can use a "Neutralizer" technique that allows it to become not as conductive.

The first thing we need to do is remove the battery and battery door and place them in a safe spot. This is because the phone can air out better without the battery, we don't want to damage the battery, and we also reduce the amount of live circuits that the water can short out.

Step 3: Method One: Heat It Up!

I live in Arizona, and here in the sunny state of AZ, we have an abundance of swimming pools. My phone has gone for a swim many times in the past few weeks, and this method was tried and proved each time.

Fortunately, here in Arizona, I can take off the battery and leave the phone in the sun, on a towel to prevent heat damage from surface contact, for about 20 minutes and it's good to go! Your timing may vary depending on how hot the sun is, but this method is my preferred.

Pretty simple, remove the battery door and battery, place them inside, place a rag out in the sun and put the rest of the phone on that. Depending on how hot of a day it is, bring the phone inside for a bit if it ever gets hot to the touch (overheating can damage LCD screens.)

Step 4: Method 2: Freeze It!

The second method consists of freezing the water inside the phone. This is by far my favorite method if your outside temperature does not go over 80 F.

Again, we start by taking out the battery.
Place the phone on two or three layers of paper towel to prevent frost damage.
Leave it in the freezer for about 15-20 minutes and take it out to test it, if it still doesn't work, leave it out for about 5 to 10 minutes then try again. Electrical components are fairly tolerant to cold, however depending on your screen, it is best to play it safe and just leave it out of the freezer for a bit to keep from damaging it. I haven't researched LCD or Plasma screens, so if anyone knows what temperatures they hold up to, let us know!

That's cool, but why does it work?

Freezing the phone works a little differently on a technical level than heating it up does.
When the water molecules inside become Ice or frost, they are less conductive (I believe due to the spacing of molecules?) thus preventing the phone from "shorting out."

This method my also lead to the problem acting up again as the phone thaws, or a worse problem acting up as the phone thaws and the water moves to a different spot.
It is also of note, that some electronic components are 'surface mounted', which results in tiny space between the component and the circuit board it self. This means that if water manages to get underneath the components and is then frozen, it can expand and cause further issues. However, in my opinion, the possibility of water getting under there with the phone only being submerged for a little while, is pretty slim.

Step 5: Unverified Methods

The following are methods that I have not verified myself. Next time my phone gets wet, I'll try some out!

1: The oven
It is said that placing the phone in the oven for a few hours at about 125 F. will solve the problem. This method sounds likely, but I would recommend taking it out now and then to test it and let it cool! And don't forget to remove the battery, cover, and SIM card!

UPDATE:
User Carolradtech has tried this method, and said the following.
I successfully baked my wet cell phone on 125 for 40 minutes and the phone is now fixed. ...the unverified baking method is now verified.

2: Rice
It has also been reported that placing the phone in a bowl of rice while putting it in the sun allows the moisture to absorb faster. As the water evaporates into steam, the dry rice can absorb it rather than have it re-condense elsewhere inside the phone.

3: Silica!
This one is similar to the rice method, it just utilizes a better drying agent. Ya know those little packets that come in jerky, new shoes, purses, backpacks, whatever, that say "DO NOT EAT" all over them? The contain little balls of a chemical called "silica." Place these in a bag with the phone, and toss it in the sun! This is potentially the best method I have heard of. It is also of note that craft shops sell silica as a flower drying agent.

4: Give it booze!
Well not exactly.. Isopropyl alcohol (rubbing alcohol) is non-conductive. It is said that if you get some, put it in a cup or a bucket, and swirl the phone around in there, it will rinse out the water and likely even clean some dust deposits! This will prevent any further "bridging" of connections as it is non-conductive, and alcohol evaporates super fast.
A few words of caution: I would try this only with the bottom half of your phone if you have a flip-phone, as I am not sure how the screen will react. Also, I wouldn't attempt it with anything less than 91% isopropyl.

Last but not least..
5: Open it up and air dry!
This is the best method hands down, but it will sacrifice any sort of warranty you had. I do NOT recommend this method unless you are entirely comfortable with it.

Step 6: Rrport Your Success/failure!

Now your phone hopefully functions as good as new! Let us all know how it worked (or didn't) and keep your information-lifeline away from swimming pools!