In the same way as most charities or non-profilts have a high profile advocate Open IDEO could do the same.
It would be started by the person evangelising about a particular success story, and then followed-up by asking people to help 'make it happen' on a range of other concepts.
This achieves three things:
1) validates the integrity of the movement
2) gets it into the media
3) gets the attention of the person's 'followers'
It could be a big name already known for philanthropic or allying with noble causes (e.g. Bill Gates, Bono, Richard Branson)
Or perhaps somebody who is very active, and a conduit, on social media (e.g. Stephen Fry)
One of the very first OpenIDEO challenges had Jamie Oliver attached to it, and that certainly got my attention