in KDE4 with dolphin file manager, and ark compression manager program installed, you have a contextual menu that enables you to simply zip and unzip your files.

Unfortunately its default compression file formats are a bit weired and you will pretty soon feel the need to tweak them. Here is how:

Open the following file in an editor:

kdesudo kate /usr/share/kde4/services/ServiceMenus/ark_addtoservicemenu.desktop

the following line is the one of interest:

Actions=compressHere;compressAsZip;compressAsRar;compressAsTar;compressTo;

for each action there is below a menu entry with all supported translations and eventually the command line.

For example to change the default compression method to the most efficient one which is  LZMA (aka 7z) scroll down to

[Desktop Action compressHere]
...various translations here...
Exec=ark --changetofirstpath --add --autofilename tar.gz %F

and change it to this one

Exec=ark --changetofirstpath --add --autofilename 7z %F

save the file, log out and log in again. Enjoy saving hard disk space!