I've literally been talking about the same idea with friends for almost a month now! We'd met with quite a few non-profits with the intentions of providing some unique contributions using our technical/marketing skills, but soon realized that the barrier to entry for that kind of assistance was high and that we'd probably do better to reduce this barrier to entry and let anyone with design/marketing/programming/etc skills help for a few hours on an existing, managed project. Our plan is to reach out to non-profits to help them generate new ideas for promoting their cause, then break up tasks and provide an interface for those that want to contribute over the web - looks pretty close to what you're doing!

I think it's great that you've put this together. I'd love to speak with you directly about your experience and how we might be able to assist you or work together in the future. If you have a minute, could you contact me at ben @ widgetinvolved.org?

Again, great initiative and best of luck.