AutoCAD DWG TrueView is based on exactly the same code as AutoCAD allowing you to view, measure, turn on/off layers, and plot just like you can in full AutoCAD.
Autodesk DWG TrueView is a gem with not only the ability to view DWG files from AutoCAD 2.x and up to AutoCAD 2010 a span of 27 years and 24 releases but also batch convert DWG files.
Autodesk TrueView also has DWG Convert built in. From the main TrueView menu just select DWG Convert and then select all of the drawings you want to batch convert.
You can even bind Xrefs, Purge, Set default Printer to None, Audit and fix, replace Page Setups, and place all files in a Zip file or specified directory. It supports the following formats for conversion:
So, a free DWG Viewer and DWG Conversion tool from the source of AutoCAD based on the same AutoCAD code, and all for free no strings attached. The new 2010 version should be available for download very soon.