ShortReckonings.com by Mikael Grave, co-founder of Webmotion

When he is not busy with Webmotion projects, Mikael works at Short Reckonings which he caracterizes as both a «lab to experiment the latest Web technologies» and his «attempt to create the smoothest user experience possible».

Short Reckonings is a free Web tool that helps you manage group expenses. It has been adopted by roommates, co-workers and travel buddies from over 100 countries around the planet.
Check it out!