[HOW TO] Create bootable USB stick from ISO in Mac OS X

Booting from a USB stick is nowadays more and more important. More and more PCs (and servers) are delivered by default without a CD/DVD drive. To install the OS of your choice, USB sticks provide you the easiest possibility. In fact, it can even work out cheaper than burning a CD or DVD that you just throw away once the version is outdated.
For most Linux distributions the ISO for burning a CD/DVD is available freely on the internet. In this post I’ll assume you have already downloaded the bootable ISO image for the OS of your choice, but how to get the ISO image onto the USB stick?