Google has added Shopping Cart functionality to its Google Checkout online payment service. The Shopping Cart feature provides sellers with a quick and easy way to offer basic shopping cart functionality on their sites. A demo is available at http://checkout.google.com/seller/gsc/beta/demo/index.html.

FAQs are available at http://groups.google.com/group/google-checkout-developers-forum/web/google-checkout-shopping-cart---frequently-asked-questions.

While the FAQs say merchants can configure taxes in their Google Checkout merchant account, it says they are "working on" shipping prices.

http://groups.google.com/group/google-checkout-api-updates/browse_thread/thread/6e3ee782f131c970