A Touch of Silliness

This works best if someone has bragged about his ability to touch his nose with his tongue. If you're determined to perform this stunt, you can bring up the subject yourself: "Can anyone here touch his nose with his tongue?" After some discussion, say, "I can stick out my tongue and touch my ear."
Don't give them too much time to think about it before you stick out your tongue and, with your finger, touch your ear.