Tonido
Tonido is an extensible and open (available under GPL and commercial licenses) platform that allows you to run your own personal web applications on your desktop and form your own private Tonido network. Applications and data are always local.
Looks this will allow you to share documents, photos, and files with other people in a group WITHOUT a central server. Looks very cool and worth trying out if you need to share files with a group of people.
