I saw Bart's Preinstalled Environment (BartPE) bootable live windows CD/DVD on the Screen Savers the other day, with it you can make your own windows bootdisk/disk-based installation, not unlike Knoppix for Linux. I haven't tried it yet, but sounds sort of like creating your own Ultimate Boot CD, except much cooler. It also looks like there's someone trying to bring UBCD together with PE Builder with WindowsUBCD, but it doesn't quite look ready yet.
Yoshi Taguri also mentions PE Builder.