The ingenuity of these exploits will never cease to amaze me.<p>I've found a few in my time, but nothing ever this cunning.<p>I once figured out that an auction site had a bug allowing a small snippet of HTML in their usernames. I changed my username so that when I bid on an item and my username was displayed on the page it hid the bid button so that no-one else could bid and I won every item for the minimum bid. That didn't last long. I got banned and got a very amusing letter in the mail from the managing director saying "Nice try, old chap."