If you have access to a PC or Virtual PC, you can try Microsoft's free Visio 2003 Viewer. Oddly enough, it opens Visio files inside Internet Explorer 6 (for Windows, of course), but seems to work ...

You can easily edit your small business flowcharts and diagrams that you created using Microsoft's Visio, and you can also export them to other Office programs, such as Word and PowerPoint. Save your ...

I have a document that has a Visio file embedded within a tab in Excel. This works fine. MIcrosoft even makes it easy to edit the Visio document. I just double click and it opens right up. It's great.