It would be interesting to have an option to pay for desired new features in existing projects. You could call it "bid for code" or something: people who need a certain feature in an open-source project would commit to paying some amount of money for it. Other people interested in the same feature could also join. A bit similar to a kickstarter, but for feature requests. Developers would choose what to work on, depending on how much money is being offered.

Is there something like this out there already? This could be a feature in this site or a completely new site if someone wants to take on this idea. Github should offer this option!