Comment The question is the wrong one (Score 2, Interesting) 190
Most community sites seem to be local run affairs by the kid down the hall in his spare time, not by those with the money to spend on SSL certs. That, and given the value of the Internet is to allow people to connect in new ways unencumbered by worrying how to pay for it suggests that the problem here is not how to provide technically secure transactions.
The problem here is how to create personaly security on the Internet. When you're in the mall, gals keep their bags so the flap is on the inside. Guys don't stare at other guys for too long. That is how they are personally secure, not because the mall guards have guns.
So a more interesting question is not "how can you make other people more secure?" but "how do you make yourself more secure?" Publish your results, and best practice will win.
The problem here is how to create personaly security on the Internet. When you're in the mall, gals keep their bags so the flap is on the inside. Guys don't stare at other guys for too long. That is how they are personally secure, not because the mall guards have guns.
So a more interesting question is not "how can you make other people more secure?" but "how do you make yourself more secure?" Publish your results, and best practice will win.