I just got an email from Google stating that Google Checkout transactions will be free until the end of the year:

From November 8 through December 31, 2006, we'll process all of your Checkout transactions for free, even if you aren't an AdWords advertiser. If you're already an AdWords advertiser, we'll process your Checkout transactions for free regardless of what you spend on AdWords.*

If you have been thinking of adding Google Checkout support to your web site, now is obviously a good time (there is a Google Checkout CFC ). Smart move from Google as they are really going to be taking a chunk out of paypal's holiday revenue, and likely gain lots of new customers.