I had a similar problem some time ago. I helped myself by installing localepurge. This freed some MB on my system, around 13, if I remember that correct.

Another solution *might* be to "apt-get install --reinstall maemo-optify-runonce" (Edit: as root, works only if rootsh is installed) and reboot (test it with "df -h" on xterm - before and after reboot). I think it has helped me once after installing several programs, but I'm not sure about how much space it freed up.

The python program bleachbit might also be helpful, but you have to go through its options first and take care of what you do, because you can brick your device.

The biggest impact though was after a recent reflash and letting HAM restore all my previously installed programs. Don't know why, but with the same programs installed I had 80MB free instead of 40MB prior to reflash... Maybe some programs from extras repository don't get optified, when installed with FAM (not too sure about this again).

Anyways: good luck.

Edit: you might also want to check for forgotten deb-files in /var/cache/apt/archives. Sometimes I found some archives there after installing via command line.