Acronis TrueImage is a hard drive imaging/cloning program. It creates an image file - much like an ISO file - of your entire machine and settings, programs, files, and so on. Another program (that I personally use) is Norton Ghost.
When I get a new computer, I clean-install it (with retail media or otherwise to avoid bloat from the trialware), install and activate programs I use (like Office), and then Ghost the drive and burn the resulting .GHO file to a CD/DVD (or span it across DVDs now for Vista), along with the imaging application (I have my images bundled with a bootable floppy image on the disc with CD drivers, along with Ghost on the CD itself).
I placed just a standard Windows 98 SE floppy image (that I got from bootdisk.com) as my boot image on my CD. In the CD itself, I place in a folder called "GHOST" the executable (GHOST.EXE), and the image (MMDDYY_OS.GHO - I date my Ghost images and then place the OS name in it, for example "010307_HOMEPRE.GHO" or "06062006_2KPRO.GHO"), along with some basic utilities, like Partition Magic or fdisk with large disk support.
Then I just start up, and issue my commands...
My 2000 install on my ancient PC can be restored in 5 minutes with my utilities. I'm planning on working on an automated backup option - the only prompt is "Are you sure?", and that's at the beginning while it's booting up.