Saw this on a Russian site and thought it is pretty funny. Picture below is a poster ad in the Moscow metro, advertising Microsoft and it's new "Now I Know" campaign they are running there.
The printed text on the banner says: "Before I wasn't thinking about this. Now I know." Somebody added another line with a ballpen, and it makes the whole ad look quite different. Oh the Microsoft, WinXP network activation, and the joys of being a legal user. ;)