Some friends of mine started http://Tripping.com, which isn't about room rentals, it's about meeting strangers while traveling globally.

But, even since the beginning, their focus has been on security. I suspect that this is the advantage of having a female CEO / Founder. She grokked that as a potential problem from the very beginning.

Jen O'Neil, is one of the most fantastic young CEO's I know. The whole team is simply amazing.