We want to use Google Checkout for our Magento store. Currently, when users clicks checkout button data is sent to Google site and the user can checkout there. We would like to make it do a silent post to Google site, that is we don't want our users to leave our site, it should look like all the processing is in our store.
This is possible in PayPal, but can it be done in Google Checkout too? Are there any examples of implementation?
If not, are there other online payment systems implemented in Magento besides the PayPal which can be used for checkout without leaving the store? I've heard something about AlertPay but I don't know much about it.