It turns out that after my thinly veiled advertisement for World Of Goo, it's actually a year old TODAY! So 2D Boy, the makers are offering to let people choose their own price for it.
In case I need to point this out...
YOU COULD GET THIS THOROUGHLY ACE GAME FOR ANY AMOUNT OF MONEY. EVEN A PENNY!
Seriously, this is amazing and you should take full advantage. Do it now!