Are there any free tools available to view the contents of the solution user options file (the .suo file that accompanies solution files)?
I know it's basically formatted as a file system within the file, but I'd like to be able to view the contents so that I can figure out which aspects of my solution and customizations are causing it grow very large over time.
A bit late for the original poster, but maybe useful to others.
Two freeware viewers for structured storage files (including .suo-files):
https://github.com/ironfede/openmcdf (old URL: http://sourceforge.net/projects/openmcdf/)
http://www.mitec.cz/ssv.html (free for non-commercial use)
When you open a .suo file in one of these viewers, you will see streams related to:
And much more...