It works amazingly, whole thing is embedded within the web browser. Autodesk also has an app for android and iphone. Unfortunately the dwg website cannot accessed using Nokia web browser (It claims that it needs Adobe Flash support, which I thought Opera mobile has....)
1. Create an autocad ws account (existing autodesk account will do)
2. Upload your dwg file.
3. Anyone, anywhere can can access your dwg and edit (as long as you give them access rights)
The dwg files can be collaborated online simultaneously. There are a lots of youtube videos that explain the features of the website.
Ofcourse, the online autocad is NOT full fledged version of the real one. But it is useful for most of the stuff you might need to do on job site or at coordination meetings. Very nice.