OK, so I've built enough machines over the years to know that a lot of the drivers that you need for a new motherboard and peripherals aren't a part of the base Windows XP CD, so they won't be auto-detected during setup.  Sometimes this is OK, because I keep all of the drivers that I need for motherboards and peripherals on a file-share on my home network.  The time when this is really a pain in the you-know-what is when Windows XP doesn't have the driver for the on-board network card, so you can't get to the network share for the drivers you need.  I figured it'd be nice to be able to solve not only that minor problem, but to also have a mechanism for other devices, such as built-in sound cards, RAID drivers, etc...

After some Internet searches, the article that I found that describes the whole process in the best fashion is this one:  http://www.pcstats.com/articleview.cfm?articleid=1703&page=1.  If all you want to do is add drivers, you don't need to do the part of the article that describes setting up for Unattended Install.  This process works and it works very well.  You can also use this mechanism to slipstream Service Packs and hotfixes onto the install CD.