Web 2.0 has brought a lot of desktop applications and collboration technique on to net. Starting with personal file storages to online office suites and net meeting. The "quick web"a result of Ajax,Flex and other technologies like SOA, have made this possible. I have recently presented many online applications and here is another: mxGraph!
Like I mentioned,mxGraph provides four types of diagrams : Workflow, Diagram (flow charts, organization charts etc.),Network and Database. I tested all four options and liked Workflow and Database. Workflow is a complete tool with very detail capablities (better that Documentum workflow manger) and is worth try for whose who design workflows and work in this area.
The other tool is the Database where you can build your schema using the UI and convert all your database development into SQL statments or export it as XML. Both these features are very useful for database design.
The mxGraph look very professional and is I am sure a try will not be waste of time!