LucidChart – Collaboration Tool and Online Diagram/FlowChart Software
http://www.lucidchart.com/

LucidChart is a web-based application that can be used to draw flowcharts, UML diagrams, network diagrams, org charts, site maps, and many other types of diagrams. Features include: 1) LucidChart offers real-time collaboration so multiple users can edit a document at the same time, with changes merged and synced instantaneously; 2) LucidChart is built in HTML5, rather than Flash, and can work on any browser, anywhere without any plugins (e.g., Flash); and 3) LucidChart is currently beta testing Microsoft Visio import which we’ll soon be releasing to make it easy to port files over from Visio. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog.