So here I am installing Leopard on an external drive on my iMac and installing various applications. One application I use now and again is Parallels so that I can run Windows and Ubuntu on my Mac in a virtual machine.
One of the things I like about running an OS in a virtual machine is that I can just copy them from the internal drive to the external drive and do not need to worry about installing Windows again, basically it just remembers where it was when I closed it down previously – even though that was on a different drive running a different version of OS X.
Nice and easy.