Still looking for that micro payment heaven

PayPal's http://x.com might have the answers with their Adaptive Payment Framwork (APF).

Adaptive Payment Framework allows you to split a payment between different PayPal account holders, for example you could sell a package of books on your site, like your lead product and an accompaning offer. With APF when the payment is take the fee and order can be instantly sent to your partner and you get to choose who pays for the tranaction action fees.

So where does micro payments come into the picture, this is one of the directions APF is going. To start with you can already carry out pre-approved payment, like when your in hotel and your credit card gets approved for payment and then as you have drinks or meals at the hotel they are taken of your credit card. APF works the same way, you could pre-approve £10 for a customer and then take payments as the customer buys good from you without haveing to login for each transaction.

To end it all PayPal has http://x.com with an open innovations API allowing you to qucikly develop new tools, see they're new apps section https://www.x.com/community/ppx/sample_apps