I agree. Our town has a website with forum section for all of the residents powered by phpBB.. While it isn't the perfect platform, it's a great way for residents to exchange a variety of information. I find myself on here every day for a variety of reasons and it's become a really valuable tool for many, many people in our town.
The Adaptive Payments / Chained Payments is exactly what I'm talking about, but it requires a redirect to paypal.com for completing transactions.
Would using PayPal Website Payments Pro to process and collect funds, then daily PayPal Parallel Payments (multiple payouts to all vendors in one api call), be a reasonable path here?
Am I missing a more elegant solution? PayPal vs. Amazon?
Here is a screenshot of the categories that were created for us: http://client.palmsdevelopment.com/frontporch.png
I would also look at Vanilla forums as an alternative to phpBB: http://vanillaforums.org/
Hope this helps!