drwxrwxrwt 2 bin bin 96 Feb 24 2004 home
Why is there a /home directory in /var?
As anomie said, clear the package manager cache.
Also check /var/log, if something is chronically broken, it could be dumping a ton of log entries.
Is logrotate installed and working? Log files compress really well, as they contain predominately repetitive data..
Using the du-h command acid_kewpie said is far more useful (so is "ls -lh" btw) than "ls -l", the "-h" option means "human readable" give you sizes in K, M, G, instead of bytes. Notice how all the directories show up as being the same size? That is how the linux file system works. "du" will give you the size of everything in the directory. "man du" for more information..
Also, check in "/var/tmp"....