Budgt - Track your ramen spending (iOS)
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!
Lunch Money - A personal budgeting tool with multi-currency support
Kittysplit - The easiest way of sharing costs with a group of friends
Pennies - Incredibly simple personal budgeting app for iOS
ihatemoney - Manage your shared expenses, easily