Hi,
Why not make a decentralised bounty system? someone with a paypal account is nominated 'treasurer' via a democratic process. There then exists a website where anyone can create feature requests. Anyone can also add a bit of money towards a feature request, which goes into the treasurer account. Then, once the feature has been completed, if a majority of pledgers agree that the feature is completed, the money is tranferred to the account of the developer who did it.
Not that I neccesarily agree with the concept of bounties in the open source world, but to me if there had to be a system that would be a logical one.
Best regards,
Chris.
chris@mccormick.cx http://mccormick.cx