Get everyone to stand in a circle, with their arms out either side. Tell people to put their left palm up, and right finger pointing down (touching the person next to them's outstretched palm).
When you say the word "GO", people need to do two things:
If your finger is grabbed, you are out, and you sit on the sidelines. The game continues until there is a winner.
The key to this game is adding a bit of drama and suspense around when you say "Go". eg count down, add a big delay, etc. You can do it a few times before it gets old :)