The Google Checkout Badge is a great way to tell Google Product Search shoppers that you accept Google Checkout payments for your products. The Google Checkout Badge can be displayed next to your items in Google Product Search if you're using Google Checkout directly on your own website. Here's the what the badge looks like.
To get the Google checkout badge to appear, you'll need to ensure two things:
1) In your Google Checkout account, your AdWords Google Checkout badge is marked as Active in the Adwords link under the Settings tab.
2) You've completed Google's required checklist.
A full explanation of the Google Checkout Badge and how to get it to display next to your Product Search listings can be found here: http://www.google.com/support/merchants/bin/answer.py?answer=160632