Two tiny programs on this site are excellent for people who have loads of AutoCAD/IntelliCAD drawings on their systems. Sometimes you just want a preview before you open a large file – and the shell extension here works like a charm. Just right-click on the file in windows explorer and a thumbnail pops up in the context menu. There is also a stand-alone dwg explorer that works equally well. Have a look at both screenshots on the website. The downloads are less than 90kb each.
Go to: http://www.jmsware.com/
Edit | 24th July 2014
Unfortunately, the link is broken