I don't know how many people know about this, and it's not on any news bulletin from Facebook, but if you want some lens flare to annoy the crap out of you while trolling through those million and a half statuses and Farmville updates, then do this: press up, up, down, down, left, right, left, right, B, A, enter and then scroll. As far as I can tell, when you navigate away from Facebook pages, the effect goes away, but in the meantime...moar lens flare!
Photographic evidence (click for bigger!):