You can actually mount ISO mirror image just with one click only! How? First you need to have a small tool called Gmount-iso to be installed on your desktop. It was written in PyGTK and Glade.

Just install with the command

sudo aptitude install gmountiso

You can use the command to do the job

mount -o loop -t iso9660 testing.iso /mountpoint

Or through the GUI at Applications -> System Tools -> Gmount-iso