So I was looking for a free alternative to MS Visio. I stumbled upon Gliffy, which seemed to satisfy all my needs in a neat little package but the major drawback of the free account was that you could only save 5 public diagrams.
So I kept on looking and I finally found Autodesk's Project Draw. Draw is a new feature-rich web-based vector drawing application which can be used to create simple floor plans, electronic-circuit diagrams, network diagrams, user interface mock-ups etc.
Though not as feature rich as Gliffy, there is no limit on the number of diagrams you can save. The diagram can also be exported out in a variety of formats.
Try it today and leave your comments behind. Personally, I liked the Gliffy interface better. It also lacks UML/ software engineering components. But it is just a test product and new features and shapes are expected to be added soon.