I always wondered that why ubuntu doesn't have any compressed filesysetem. When I use Windows, I used compressed function of NTFS to save my disk space. Actually I could save much of disk space when I compress file such as text files and incomplete torrent files. But after change my main O/S to Ubuntu, I can't do that.
Today, I found one; fusecompress. http://developer.berlios.de/projects/fusecompress/
That makes any filesystem to compressed filesystem. And it has many options to change compress ratio and performance. It has better compressed ratio than NTFS's one.
So I tried to find fusecompress deb package for Ubuntu. But I could find nothing. Instead of I found a needs-packaging bug report: https://bugs.launchpad.net/ubuntu/+bug/108874
To use fusecompress, I have to install manually from source code. After compiling, I could run fusecompress, and make and compress my ext3 filesystem.
It's very nice and works perfectly nevertheless it is still beta state!