DWF

Autodesk Design Review is an application for viewing, markup, and printing of DWF files. If you have DWG Trueview installed also, you can "open" DWG files with it. Actually, what it does is use Trueview to open the DWG and plot it to DWF using the last saved plot settings.
 
Best that I can tell, you have two options for getting this application
 

• Download a tiny (271k) executable which is just a launcher for an online install. The destination computer must have internet access to install this version.
• Download a massive (743MB) file that contains Design Review along with both the 32-bit and 64-bit versions of DWG Trueview

Links below.
Design Review 2010 install app (±271k)
Design Review 2010 + DWG TrueView 2010 (±743MB)

Since the DWF format has been gaining steam over the past couple of years, one of the requests I have seen a lot is for the ability to automatically create a DWF at the same time you save or close a drawing in AutoCAD. Starting with AutoCAD 2008, you can now do this.

DWG TrueView 2008 is available for download. If you want to read more about it and fill out a form prior to downloading, go to http://www.autodesk.com/dwgtrueview

Now that Autodesk has made Design Review available for free, you may be wondering, "do I need this?", "what is it?", "what does it do?", "why is it all of a sudden free?", "where can I get it?", etc.

I found an excellent review of this product at "Stress Free" that should answer all those questions and more.

Take a look at Reviewing Autodesk Design Review