VirtualBox is a great tool for testing operating systems, whether for testing a different distributions or simulating a network configuration. What follows is my experience installing and configuring Fedora 17 on my notebook running Ubuntu 12.04 LTS.
First off, this pseudo tutorial assumes a few things are in place. The Ubuntu Desktop is installed and running with VirtualBox installed, and the Fedora 17 ISO has been downloaded. Though my notebook has a 64-bit processor, it does not have the virtualization extensions; something I didn't verify before purchasing back in 2008. So, even though I'm running the 64-bit version of Ubuntu 12.04 LTS, I'm running the 32-bit version of Fedora 17 in a virtual machine.