Before I go to all the trouble of testing an approach and relaying the captcha, has anyone else automated Google account creation for the purposes of streamlining Google Checkout implementation?
Especially in a manner conforming to Google's terms of use.
It looks like you are looking for a Google Checkout "Guest Account" - a one-time account where the customer does not have to create a Checkout account with a username / password.
Read the Google Checkout Terms of Service (section #7 - Time Checkout Account):
https://checkout.google.com/termsOfService?type=Buyer
This Checkout Merchant forum question has extra details:
http://www.google.com/support/forum/p/checkout-merchants/thread?tid=456542dc4fd031db&hl=en