Power Archiver 6.1 : Very complete compression program. Newer versions are shareware, but this version comes with a nice EULA that says you can distribute it anywhere to anyone. This link is a direct download to the program on some other webspace I have. Simply right click the link and select save as to save locally. I found another link to the file (I was forced since AOL killed all their "member" hosted websites.
7-Zip : A file archiver with highest compression ratio and distributed under the GNU LGPL. Not as user friendly as PowerArchiver, but does what it says.