Let's start off with Yahoo who was granted the patent — Systems and methods for implementing person-to-person money exchange. Filed in 2000, the patent is described in it's abstract as:
Systems and methods for effecting online financial transactions between individuals or between individuals and entities such as banks, merchants and other companies. Each user accesses a fund exchange server to establish an online account, which is used to transfer funds to and from other entities' online accounts. To fund an online account, funds can be transferred to the online account from a credit card account or from another online account.
To me, this sounds somewhat simillar to Google Wallet, GPurchases, GBuy, etc. or atleast something along those lines 😉