Not only does this look like it'll work, it should be very easy to use. I can't tell what method it may use for cloning/imaging, but if the download is either a bootable CD image or the program makes one that would be my best guess. The problem with cloning XP (and all other Windows OSs) is that it's generally impossible to do while the OS is running because of all the dependent files Windows keeps open just for the OS. Thus the need for a tool that runs without the OS. (There is at least one tool that will make a "snapshot" of these files, but I don't know whether to trust such images to be 100% correct.)
Oh, and thanks for the link. This will be useful even if I don't use it to image my XP installation.