To the ever-growing list of free on-line Flash applications that replace desktop applications, you can add Draw Anywhere. Draw Anywhere allows you to create flow charts, process diagrams, organization charts, and diagrams similar to the way you would in Visio. You can choose from a variety of templates and shapes, drag them around, connect them with various types of lines, add text, all of the usual stuff you'd expect from a desktop application.

Screen shot of Draw Anywhere in action