For those of you who haven't seen this yet, you should check out Autodesk Freewheel.
Freewheel is a web-based service that allows you to share 2D and 3D designs quickly and easily.
You can zoom in and out, pan, orbit (in 3D.) You can even email links to specific views within the viewer. The project below is a sample set of documents from Autodesk. I invite you to play with the tools. There are 29 pages browse, better get to it.
I think that applications that provide sharing like this are going to be essential in the adoption of BIM.