I like that one (the number row/column/diag thing). good stuff.

someone sent me this the other day:
http://flash.qbol.net/pl;p/youxi/images/04042203.swf

It came with a note saying:
There are 13 items hidden in this room in order to let you get out of this room.

If you found:

0-6 items, your IQ is very low, total idiot

6-8 items, Low IQ, u r an idiot

9-10 items, u r normal

11-12 items, your IQ is high, above the average.

13 items found and get out of the room, there are less than 4000 people in the world can do it.
Frankly, I think that's rubbish. Especially when the link (not the one above - you'll see if you try it) is broken. But if IQ means "having the patience to click every millimetre of a screen" then I guess my IQ is pretty low.