Until very recently, mounting an ISO image on Windows required installing some additional software, but over on the Mac OS X side of things, you can easily mount an ISO image by simply double-clicking on it.
There are also two other ways to do so — the first is by opening up Disk Utility and going to File -> Open Disk Image. The second way is by opening up a Terminal window and typing something similar to the following:
hdiutil mount filename.iso
Did this really require us to write up a tip? Not really.