I would take part in something on Sanibel Island next March. I've been visiting since I was a kid, and really enjoy it.
How about... Startup Node 2012: One month at an reasonably affordable, family friendly destination. Provide a designated place to collaborate (in the spirit of startup weekend or bar camp), and an online presence to include remote collaborators (so people can join in before and after the time that will actually be there). Just sell 'tickets' for $20-$50 or so, and give attendees access to a Google apps/docs account (i.e. hn-id@2012.startup-node.com)... and github, of course.
Ad-hoc mingling at the Mucky Duck on Captiva from 4-5 (before they open for dinner).
Sounds fun to me :)
