On my ThinkPad, I use either Norton Ghost or Acronis True Image to clone the hard drive. This takes less than two hours. Then I swap the drives and run the laptop off of the copy. To me there are two advantages:

1. I know for sure that my backup is bootable.
2. I know that if the drive in the laptop fails, I can insert the other drive and boot without any recovery process.

The downside is that 80Gb laptop drives are quite expensive.

I still use a pair of old IOmega devices for my home machines; Jaz (2 GB) and Ditto (35 GB) tape drives. The Jaz drive runs fast enough that you can actually run applications from it, but the Ditto drive takes about three geologic ages to back up a HDD, assuming the drive's size isn't greater than Ditto can handle.

We also have a SCSI DVD/RW drive and plenty of spare media lying around the house. Can't overestimate the usefulness of that.

On the edge of the topic, I've come across the "Universal Imaging Utility" from Big Bang LLC / Binary Research Intl. (I've downloaded their trial version but won't be testing it till this weekend at the earliest). Basically, it allows you to create a Windows image file using various Windows imaging software which will then work on multiple hardware. You're still using your own imaging software (Ghost, DriveImage, etc.) but you can restore that image to a desktop (or deploy it to multiple PCs) and the entire software system is intact. The kicker is pricing, which starts at 10 licenses (@ $19 each) plus $20 for media (which you need at least one set of), so the minimum cost is $210.

The only fine print I see: 1) the image file is larger (because of the driver base it contains), 2) when dealing with ACPI-compliant (within the last four years or so) vs. non-ACPI compliant (older) PCs, you need to create two image image files, and 3) support for SCSI drives is still on the way (but it does support all ATA / SATA drives, and ATA/SATA RAID controllers).

Anyway, it might be a useful/necessary utility to someone here...

External USB / Firewire Hard drive
 

I use a external hard drive for my backups. I do not back up things like the OS or applications since I can re-install them (yes, it is a pain but workable). WHat I do is create a primary folder called data with sub-folders by application. THen all I need to do is connect my external device and drag the entire folder over too it. Very easy painless and fast and I did not need to buy any extra or specail software to do it. :D