Google is using some of their vast cash to get us acquainted with Google Checkout.
They are currently offering $10 off orders over $30 or $20 off $50 orders if you simply use this option during the check out process. Buy.com currently has this option, along with cheap prices, free shipping (on a lot of items), and no tax (except CA, MD, MA, and TN)!
Google is only running this offer through ???, so take advantage of it today!!! In addition, you can re-use this coupon on seperate orders with out having to create 'new' accounts.
FYI - this deal/coupon only works on in-stock items (not pre-orders or items that are back-ordered) unfortunately...
Here are the steps:
1) Click this link: Buy.com 
and shop around. Add items to your cart/etc...
2) Upon proceeding to check out, select the 'Google Checkout' option (make sure you are not currently logged in to your Buy.com account).
3) If your order is over $30, Google will spot you $10... If over $50, Google will spot you $20!
Repeat steps 1-3 to create individual orders (over $30 or $50) that can use the coupon...