Volunteering your 3D printing skills
I'm getting involved in the 3D printing movement and looking at the potential to match people with the skills in 3D modeling (CAD) with kids who need custom made 3D printed prosthetics fit to their body. If you know anyone on either side of that fence, let me know.
Organizations like VolunteerMatch are a good fit, but they're too broadly focused to work in a niche like this.
I was first inspired when seeing Bre Pettis talk to Martha Stewart at CES 2014 about how quickly kids outgrow these very expensive devices.
And here's more info about the possibilities: http://boingboing.net/2014/01/16/medical-makers-3d-printed-pro.html