Is your keyboard filthy?
Put it in the dishwasher, dry it a bit and it's crisp and clean again!
Really!

http://discussions.apple.com/thread.jspa?threadID=835843&tstart=15
and
http://www.mopacmedia.com/shared/resource_viewer.php?Resource=307

Please do tell me the results if you have tried this at home (got a real filthy one myself so...)!