֪ͨapi http://code.google.com/intl/zh-
CN/apis/checkout/developer/Google_Checkout_XML_API_Notification_API.html
checkout api http://code.google.com/intl/zh-
CN/apis/checkout/developer/Google_Checkout_XML_API.html#https_auth_scheme
precessing api
http://code.google.com/intl/zh-
CN/apis/checkout/developer/Google_Checkout_XML_API_Processing.html#notification_api
定制购物车
http://checkout.google.com/support/sell/bin/topic.py?hl=en&topic=8671
开发论坛
http://groups.google.com/group/google-checkout-developers-forum?pli=1
