Installing VirtualBox was a little bit more complex on Linux. The first time I ran the installation, it stopped at the end complaining about not finding a kernel module or the kernel headers to compile a kernel module.
After installing the kernel headers, I tried to run the installation again but the installation would just stop indicating that the vboxusers group already exists, so I un-installed the virtualbox-2.1 package with a "dpkg -r" and tried re-installing again, but the group was still there :-(
Anyway, so I manually remove the vboxusers group using "groupdel vboxusers" and re-install again. This time, I get a message indicating that the installation was successfully completed and the kernel module has been started.
Finally, I've got to go find the executable as there isn't an icon in "Applications". I remembered seeing a System Tools menu in "Applications" for my last install, so I figured I could just get it by logging out and logging in again, and guess what - I was right!
I launched Virtual Box, scrolled down and accepted the license agreement, cancelled the registration (I'll do it another time, I promise!) and went ahead to create a virtual machine to try a boot. It worked beautifully!
The next step for me is to install Windows on VirtualBox, but I'll have to try that another time.