DrawAnywhere.COM - Free Replacement For Visio?
Draw Anywhere is a free online diagramming tool that allows you to draw all kinds of charts and share it with others. Draw Anywhere allows you to login from anywhere and edit the diagram. The best part of this free online diagramming tool is that you do not need to download or install anything. You will be able to export the diagram into an image file including PNG, JPG, TIFF and GIF. These features make it makes it an an easy to use free replacement for Visio.
Link: Draw Anywhere - easy online diagramming, flow chart
Other Visio altenatives:
Link 2: ArgoUML: Free and Open Source UML Modelling Tool
Link 3: Free Replacement for Microsoft Visio: Dia [Windows version]