Since I use XP via VM, activation could be a concern for me...but usually isn't as I prefer to do a P2V with an already activated source. If I am forced to do a fresh install, it is easy enough to use the activators that I've kept on hand for just such an event. It helped for me, seeing just how terrible vista was right away - and so I made sure to safely store what I was certain would be needed later...
I haven't used cracks for XP in years... basically every motherboard where I have installed XP contains the SLP strings used for OEM activation, so all I need is 2 OEM keys for Home and Pro, and replace the OEMBIOS.* files with the ones compatible with the SLP string, hence no online activation required. If for some reason there's No SLP string, I use XP Pro Volume.
That's not allowed and useless. OEMBIOS files are the way to go. And VL doesn't require online activation either.