On the right click menu (in Nautilus, desktop, etc), there is a "compress" option. Is there any way to make "zip" the default format for this?
After some investigating, it appears that this is controlled by a gconf setting. To set zip as the default compression method, hit Alt+F2 to launch the 'Run Application' window. Type 'gconf-editor' in the box and hit the 'Run' button. This can be seen in the screenshot below.
Once you hit the 'Run' button, a window like the one below will appear. This is the Configuration Editor.
The compression feature of nautilus really uses
Next, find and expand the 'file-roller' folder.
Expand the 'dialogs' folder.
Select the 'batch-add' folder.
You should now see an item with the name of 'default_extension' in the section on the right. You will want to click on the 'Value' field and change whatever was previously there to '.zip'.
Now, if you close the configuration editor and open nautilus, .zip should be the default compression method.
Well, when you click on «compress» it will show you a window to select the format. The file format is the last chosen format.