The other gotcha you need to watch out for in moving things to /media/mmc* is when the card is mounted vs. when the OS wants things. I tried moving all of the python stuff over and quickly broke stuff as some of the python libs were wanted before the mmc cards were mounted.

Another good candidate to move is /usr/games. I also move /var/cache/apt.

BTW: It's best to make a backup of /usr/share/locale (tar -zcvf /media/mmc1/locale-backup.tar.gz /usr/share/locale) before you start deleting things. Strange stuff happens with displays when you accidentally delete too much.

- John