Ok, some people haven't been paying attention.
There are tons of tools that make migration painless, especially with Vista. (There are several 3rd party tools as well)
Microsoft has tools designed for migration from machine to machine and works so fast and slick you wouldn't believe it comes from Microsoft.
http://www.microsoft.com/downloads/details.aspx?FamilyId=39F724EB-4E37-4BE0-ADFC-786786E73E50&displaylang=en&clcid=0x409
http://www.microsoft.com/windows/products/windowsvista/buyorupgrade/easytransfer.mspx
Easy transfer is the original tool designed for User profiles and documents and settings (like the XP Migration tool).
The new version is Transfer Companion, and not only does all the user profile (or multiple provfiles), documents, but ALSO transfers all the installed applications and settings to the new machine (even leaving the software activated.)
This is a install software and click, it will transfer live from machine to machine via USB, network, etc, as well as a stored location that you pre-configured and shoved the data to, like an external storage drive.
If you are migrating or moving around much, you should be using these tools. Also pay attention to MS's new Mesh technologies, as it will move user profiles to centralized locations available via the internet like current Windows profiles are hosted on local domain servers. i.e. you will be able to flip a switch and have your desktop appear on any computer in the world in a matter of seconds. (Intenet based roaming profiles and data.)