Sure, you could load up a flash drive with diagnostic, anti-virus, and data recovery software to fix up a sick computer, but it's kind of boring. If you've got an old iPod kicking around you might as well turn it into the hippest computer recovery tool around.
TechTool Protogo is a suite of diagnostic tools for your Mac designed to be loaded up on an iPod. I would be all about getting this on my old 10GB 2nd gen except for two small problems: I have a PC, and it's a whopping $150 for the software. Someone out there has got to be able to whip up a suite like this that's all freeware and can have the same iPod functionality. Let's see it, dudes.