We make use of the DWF file format for sending drawings to clients for review or print shops to print. It is a significantly better format for sending drawings than PDF. Not only are the files a fraction of the size, but they are also easier to create. In addition, the DWF format gives our clients the ability to measure and to make notes or mark-ups that they send back to us.
The one glitch has been that it was not readily available for Mac users. There is a solution through third party software, McDwiff. It is a free download for private users and $39 for commercial users.
If you have a PC, you can download the Autodesk version.
Dean talks a little more about the DWF format.