Bestfit is a small program to determine which files that should be put
on a CD (or other media), so that as little space as possible is wasted.
It is very easy to use: you specify files on the command line, and 
bestfit prints the names of those that were selected. Alternatively, 
bestfit can execute a command for each selected file (eg. to move them 
to a different directory).

WWW: http://oskarsapps.mine.nu/bestfit.html