Are you a remote administrator? Do you keep tabs on systems not in the same city or even state? Then you might want to consider out of band management. This lets you access and control a machine whether it's powered on or not. It's pretty impressive what you can do with these things, and it bypasses the operating system. So if you need to shut down a server that's hanging, you can turn the power off and back on remotely. The Dell version of this is called a DRAC, for Dell Remote Access Controller. HP has a system called iLO, Integrated Lights Out. Of course, I'd be tempted to use it even if I was in the same building as the server in question. I have, in truth, used this while standing right next to the server, but admittedly that was while learning to use one.