Gliffy is easy, free, and fun to draw diagrams on web!

    * Diagramming in your web browser without downloading additional software
    * Desktop application feel in a web-based diagramming solution
    * Add collaborators to your work and watch it grow
    * Link to published Gliffy drawings from your blog or wiki
    * Create many types of diagrams such as Flowcharts, UI wireframes, Floor plans, Network diagrams, UML diagrams, or any other simple drawing or diagram