The new ‘Google Purchases’ service (purchases.google.com) will be launched in a few days, and is to allow users to make micropayments within ‘Google Base’ (buy and sell all kinds of items), to acquire licences of ‘Google Earth’, non-free videos from ‘Google Video’, and to pay products of the Google Store.
Users only need their ‘Google Account’ (it’s free and your Gmail account is your pass), and they have to add their credit or debit card information (only Visa, MasterCard, American Express or Discover are allowed). For security reasons, it’s not allowed to use the same credit card for more than one Google Account.
Right now it’s just intra-Google stuff. Soon to expand, I’m sure.