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!
Mint - Free personal finance software to assist you to manage your money, financial planning, and budget planning tools. Achieve your financial goals with Mint.
Kittysplit - The easiest way of sharing costs with a group of friends
GnuCash - A personal and small-business financial-accounting software, licensed under GNU/GPL and available for Linux, Windows, Mac OS X, BSD, and Solaris.
SplittyPie - Create event, add users and their expenses.
HomeBank - HomeBank is a free software. Use it to manage your personal accounts. It is designed to easy to use.