I tend to get this call even more often then the "My password doesn't work." phone call. It's the ever so popular "My keyboard is broken and I can't type - fix it!" call. I will remote desktop into their machine and check it out. Doing my usual thing saving documents and checking the device properties.
8 times out of 10 the keyboard is unplugged and does not show up in device manager. There is a 1 out of 10 chance it is the batteries going dead in their wireless keyboard But, there is the occasion that the keyboard is actually broken (the end user normally has spilled something on it.)
Sure this is one of those physical jobs that someone needs to walk on over to the machine in question and smack it around a little. BUT if your user NEEDS to type in a password to clock-in or something urgent you can have them open up the little know XP and Vista On-Screen Keyboard via the mouse.
Don't support end users? How about a machine that has a busted caps lock, num lock or some other key you HAVE to be able to hit during an install?
Do you back down and look for another keyboard? Hell No! You open up this biatch and do what you have to do like a good Admin!
Do you use the OSK for something? Let us know in the comments!