Today, my Thinkpad T61 decided to stop working. While I was in the middle of reading email, it just stopped. Completely blacked out -- no AC light, no battery light, nothing. Here's how I got it working again.
Tyler pointed me at an electronics ad for some really cheap, really tiny USB keys, so I picked up a couple today. They were 128MB, $9.99 each, and are about the size of a penny:
128MB isn't much nowadays, but it's more than enough to store SSH and GPG keys, or maybe a copy of GTD TiddlyWiki. I'm sure I'll find other uses for them too, but hey, if I don't, they were only $10 each.