Konami code!!!!

By entering these keys:

Up, Up, Down, Down, Left, Right, Left, Right, B, A, Enter.

You will activate the famous Konami code, which unlocks secret areas of many well known websites.

Entering the Konami code in Facebook causes the Website to Enter Lens Flare Mode... TRY IT OUT YOURSELVES!!

Source: http://facebookflow.com/2009/09/05/two-fun-facebook-tricks/