Actionair of the United Kingdom makes fan coils and dampers. They show off their products using DWF and PDF.
Check out those file sizes! Their site supports DWF for users with the Autodesk DWF Viewer or Autodesk Design Review by providing links to DWF files. They support users without by using the Project Freewheel Viewer.
You can get to the Freewheel section by selecting Products and then Drawings. Action Air also makes the original drawings available via i-Drop.
This is definitely DWF in action.