This deal has ended.
Buy.com has the Logitech Playstation 3 Controller for just $9.99 after a $20 mail-in rebate. But more importantly, new Google Checkout users who sign up and pay via that service get an additional $10 off discount that makes the controller free after rebate, effectively. Not new to Google Checkout? Just setup a new Gmail account and you're good to go. Plus, shipping is free and there is no tax (except CA, MA, MD, TN).