I finally picked up another USB key for storing my documents on. I figured on using the older key (128M) to hold a bootable Linux distribution. I use a number of bootable CD distros, but, I really like DSL as it is quite small, recognizes all of the hardware I have here and the default settings and applications fit what I need it to do.
I booted my main box using the DSL CD and followed the instructions to create an USB version. When I rebooted the machine it didn't boot to DSL. I neeeded to change the boot options of my box to recognize USB-HDD as the option. Once I made that change it booted to the DSL USB device without a problem.
It is a nice tool for an emergency if the CD drive is not working and you need to boot an unusable machine. I will need to explore the options available for backup/restore and eventually look at customising the USB drive. I have a few packages that I prefer that are not on the distro and others I don't want.