A couple of days back I accidentally let some drops of coffee with milk fall on the direction keys of my keyboard. I immediately wiped them dry, but the harm was already done. The next day, the "down" arrow annoyingly got stuck whenever I pressed it. Obviously, a portion of the liquid got into the key well and became low-tac glue.

Before I waxed irrational and ran screaming in terror to my nearest computer store to get a new KB, I took a deep breath and Googled for a solution. This instructional video at eHow was the best one so far (at least in my particular case). (I'm only including a link instead of embedding the video since I couldn't stop it from auto-playing.)

As good as new

Once I pried off the direction keys, it was a relief to see that it wasn't that much of a mess. The liquid only got to the well, or recess, of the keys, and not into the rubber membrane and circuitry within, so I was able to fix it by cleaning the keys and the well with isopropyl alcohol and some Qtips. Within minutes I got it dry and in working condition.