RPX[1] is doing some interesting things with Patent Troll Insurance, but it's really only a viable option for huge corporations who want to buy into the troll-defense patent pool.
[1] http://www.crowell.com/NewsEvents/AlertsNewsletters/all/Cour...
[1] http://www.crowell.com/NewsEvents/AlertsNewsletters/all/Cour...
It's probably better than nothing, but actually removing the patents and allowing open competition is more beneficial for the public and economy overall.