A cool, collaborative drawing tool

Most of you use or will be using Visio to create diagrams. I just came across Dabbleboard, a vector drawing service you might find useful.

It is not as capable and flexible as Visio, but it is very easy to use, extensible -- you can reuse shapes and shape libraries you and others create -- and, of course, it is a networked application.

Several people can work on the same drawing at the same time, and the drawing can be made public or shared within a limited group when it is published. You can create libraries based on your drawings, and there are also public libraries and tool kits.

If it sounds interesting, check this how-to screencast.

Dabbleboard has several features that facilitate and encourage collaborative work. What features would you like to see them add? What do you think the community of Dabbleboard users will add? When would you use Dabbleboard instead of Visio? When would you use Visio?