Originally Posted by SiO2

Guys, I don't know whether this information deserves a new topic but yesterday I've found a way to clean the N900 rootfs that worked fine on my device. Please handle this information with care, since I've read about people running ubuntu or debian who got the system erased by this command.
I've typed this (as root):

apt-get autoremove

my free rootfs increased by 8% but before I recommend to try this:

apt-get --simulate autoremove

this command simulates the autoremove action so, you can check the output in order to be sure that only useless packages will be removed.

Try also: apt-get moo

This won't help you in rootfs cleaning but is absolutely safe! ;-)