Google introduced their online payment processing system Google Checkout in June. To promote it retailers using Google Checkout gave $10 on purchases over $30, now Google increased the rebate to $20 for purchases over $50.
$20 is starting to be an interesting rebate and it just comes right on time for your holiday shopping. The only problem is to find a decent shop where you can actually use Google Checkout. I know of only two larger electronics online stores that have implement it and also that give the $20 rebate: Buy.com and RitzCamera.
You can find all stores supporting Google Checkout on the Google Checkout store directory. Even with a $20 rebate it is always good to compare prices first. You can use our shopping.com powered site or our I4U Pricewatch site that combines Amazon.com offers with Shopping.com price comparison.