Spilled stuff on my iPod, USB cable port doesn't work
If it's still under warranty, absolutely take it into an Apple Store (not an authorized Apple repair shop) and talk to one of the Geniuses. Tell them the story, and above all be completely honest with them.

I've had my iPhone 4 replaced for a faulty home button, but couldn't reproduce the symptoms. My friend, the same deal (we really did try with his, but just couldn't reproduce the issue). My other friend dropped her iPhone 4 from a truck, smashed the glass. They happily gave her a new one, no hassle. My brother, same exact deal (although he did not drop it from a truck, but rather it fell from his pocket).

Some Geniuses tell you they charge $299 for a replacement, but will often waive that fee the first time. Other's will smile and make your day.

I encourage everyone I know to put Apple's legendary customer service to the test.

Now if it's not under warranty, cleaning it before it sits on there too long and likely corrodes the connectors is an excellent idea. You want to grab a q-tip (cotton swab) and some isopropyl alcohol (try to grab 99.9% pure if you can). Do not use anything else, it will harm the connectors. And again, I strongly suggest you do this soon.