First I have not written a module to handle this, but just wanted to let folks know about a new player in the game. This is not an endorsement since I haven't tried it or looked at the detailed API yet
Amazon is opening up access to their payment system.
http://aws.typepad.com/aws/2007/08/pay-me-now-or-p.html
Amazon Flexible Payments Service (Amazon FPS) - Limited Beta
Amazon Flexible Payments Service (Amazon FPS) is the first payments service designed from the ground up specifically for developers. The set of web services APIs allows the movement of money between any two entities, humans or computers. It is built on top of Amazon's reliable and scalable payment infrastructure.
Amazon FPS offers developers unmatched flexibility in how they can structure payment instructions, including standing instructions that can remain in place for multiple transactions. These instructions impose conditions and constraints on money movements and can be set by both senders and receivers of funds. For example, a sender might set a spending limit per week for a particular named recipient. Only that named recipient would be able to withdraw funds and only up to an amount per week equal to the spending limit. A piece of FPS functionality called the GateKeeper automatically enforces the constraints you set with payment instructions. When the sender or receiver is a computer system, payment instructions are set programmatically using APIs. FPS also provides a simple set of user interfaces that humans can use. From the users' point of view, they simply see terms of service and a request to accept those terms.
Developers are free to set up an unlimited number of payment instructions. This makes it possible, for example, to have a different set of payment instructions for each counterparty with which you do business.

Comments
interesting.
Hi MacRonin,
It's interesting and great to see new players entering this market...along with google's checkout payment system it should, hopefully make the market more competitive and reduce the reliance on paypal.
In case others are wondering...here's a copy n paste of the Amazon FPS pricing. more details here
Pricing
There are no minimum fees and no start-up charges to use Amazon FPS. In addition, use of the Amazon FPS Sandbox is free of charge.
Fees are assessed on a per-transaction basis and vary depending on the payment method used and the transaction amount:
For Transactions >= $10:- 1.5% + $0.01 for Amazon Payments balance transfers
- 2.0% + $0.05 for bank account debits
- 2.9% + $0.30 for credit card
For Transactions < $10:
- 1.5% + $0.01 for Amazon Payments balance transfers
- 2.0% + $0.05 for bank account debits
- 5.0% + $0.05 for credit card
For Amazon Payments balance transfers < $0.05:- 20% of the transaction amount, with a minimum fee of $0.0025
Qualified developers can apply for the following monthly volume discounts for credit card transactions:Learn how you can qualify for volume discounts.
Note: This fee schedule is for payments by US customers only. You can allow non-US customers to pay using credit cards (not Amazon Payments balance transfers or bank account at this time) for an additional charge of 1% of the transaction amount.
more details here
Dub