I have set up a website where people can place small money bounties for
open issues oon JBoss JIRA (or any other open issue tracker)
So far it's only got a few offers - but it's slowly growing and people seem to get pretty interested on the idea.
I really think that as it gets more popular, such a tool can have a
big positive impact on a lot of open source projects, especially
popular ones like Arquillian.
Please take a look -->
There's also a JIRA plugin that will add a (discrete) "Sponsor this issue" link on the "view issue" page, that will let the user add a sponsorship for the issue on FS.
It's already being used by the Jenkins Project (see it in action here).