Splitwise - Splitwise is a free tool for friends and roommates to track bills and other shared expenses, so that everyone gets paid back. On the web, iPhone, and Android!
Airbnb - Book unique places to stay and things to do.
Splittable - Shared living made simple
Roam - Live anywhere you want, as long as you want.
EquiTable - Split the bill fairly
Outsite - Flexible co-living membership for $99/year