I just compressed a folder with 61.3 MB of DWG files down to 4.67 MB
with the freeware archiver "7zip"
formatting link
I used the "maximum" compression setting for the .7z format, but there
was still an ultra setting that can compress the files even further.
I just wanted to pass this along to the group because it really seems
to be a good way to send large DWG files via email, or to help save
space when doing backups.
John