> tiny proportion of the most technologically sophisticated banks provide the ability to transfer money to any arbitrary person
My experience is that every US bank has an "external account" transfer feature (for use with your other accounts) that can initiate ACH credits or debits, as well as a "Bill Pay" that will do ACH credits to any routing/account number. But (as I alluded to) banks limit the dollar amount of transactions initiated through them, as they are responsible for cleaning up any mess due to "fraud".
