GUI rar 7zip and zip support in Ubuntu

Once I downloaded a 7z file and it wouldn't open. First I thought that the archive was corrupted so I downloaded it from another mirror and I got the same error.
Then I realised that Ubuntu doesn't come with support for .zip and .7z archives allthough Backtrack 5 r3 does have support for .rar, .zip and .7z by default.

To open .rar, .zip and .7z archives in Ubuntu open terminal and type:

For .zip

sudo apt-get install unrar-free 

For .7z

sudo apt-get install p7zip-full 

For .rar
       sudo apt-get install peazip

These small things are annoying for beginners. I'll add them to my installscript for the next version of Ubuntu.