Ubuntu 5.10 - Cleaning up the space

Here are some some ideas how to clean up the space.
1) Run the following command:
sudo apt-get clean

2) Clean up synaptic's downloaded files

3) To estimate file space usage, change directory to root and use du command:
cd / sudo du -hc --max-depth=1 
Here is example of what is printed for me:
48K     ./lost+found
14G     ./media
36M     ./etc
76M     ./var
90M     ./lib
2.4G    ./usr
4.0M    ./bin
7.7M    ./boot
2.9M    ./dev
732M    ./home
4.0K    ./mnt
507M    ./proc
23M     ./root
8.4M    ./sbin
72K     ./tmp
0       ./sys
4.0K    ./srv
4.6M    ./opt
4.0K    ./initrd
4.0K    ./debootstrap
4.0K    ./_F
1.4G    ./_D
4.0K    ./_C
37G     ./_E
2.1G    ./_sky7
12K     ./Xilinx
58G     .
58G     total