+1 for XP mode. However, I have found that it is intensely slow to load up... to the point that I rarely use it. I had intended to learn how to use ArcGIS 9.1 properly but find that the double whammy of apathy (I had three years during which it was installed on my XP machine and *almost* never opened it) and the slowness with which XP mode opens and closes means that I rarely use it.
NB XP Mode is nice and quick once it has loaded. I WISH that the VM that XP Mode comes with and loads under would run prior versions of Windows - I'd love to play around with a VM of 3.11 (nostalgia). Finally, I have 4GB of DDR2 RAM on my notebook and it's maxed out. I have assigned 2GB to my XP VM. This may explain the lethargy with which XP Mode opens and closes...