The User State Migration Tool (USMT) is what you use to move lots of users from one operating system to another. It moves files and settings from their old PC to their new one with the minimum of fuss and is a great tool to use when implementing your Vista deployment!
One drawback is that it's a command line tool and whilst this might have some of you clapping and hankering to get your hands on it, others of you might be wishing there was a version with a graphical user interface.
Well now there is.
Dan Cunningham has come up with this nice looking .NET app that wraps up all that command line loveliness in the an equally pleasing (for some) GUI. Dan has more details and hat tip to Richard for finding this.