There's been a lot of questions centering on Software Tools for System Administrators. But I would like to know about any odd physical tools or techniques that you've used; Something that you never expected to be useful, but ended up saving the day.
I'll go first:
A Camera Phone.
An application server had a major power issue that borked the RAID. Many of the disks were offline. Before I took the plunge and forced disks back online, I took a picture of the RAID BIOS screen with my camera phone. Having the exact layout of the RAID stored safely in my pocket, I was able to reset the RAID, and reboot the server.
What odd tools/techniques have you used?