If you are running near the end of your disk space, the information here may help you.
Command line tools to see which package are using the most disk space:
aptitude -F '%I %p' search '~i'|egrep '^[0-9]+[\.,]?[0-9]*[MG]B'|sort -n
Tools to erase
files you do not want
packages you do not want
Tools to alter files to reduce them
strip --strip-unneeded upx-ucl