Yeah, I picked this up yesterday. When clicking on the Buy Now! link, the next page didn't load and then the whole homepage crashed and wasn't available for hours. Too many people trying to access the website I guess.
But it's all OK today. Just wanted to note that you're not actually
buying the game, more like
donating an amount of dollars you see fit via Paypal or Credit Card. It can be either 1 cent or 100 dollars (or more)
At the end of the transaction, you get an e-mail containing an option to either gift the copy you just bought to someone else or keep it. This way, there is a reason to buy multiple copies (some for friends or family members, one for yourself).
After you made your decision, a special link will be sent to your inbox where you can download any of the existing versions (Windows, Mac and Linux) DRM-free. If you're having problems receiving your download link (because the servers are overcrowded again), here is a link where you can re-send the confirmation letter to your address:
http://worldofgoo.com/manualEmailBot.php