Well, at home I usually use the name of the room the computer is in + "COMPUTER" or a slight variation on that.
When I worked in the local university they had a naming system which was like this:
DEPARTMENT + "PC" + NUMBER
Computer 123 in the Geography department.
At my school they have a slightly more elaborate system which is like this:
ROOM + "-" + MAKE + "-PC" + NUMBER
Computer 12 sold as a Dell, in the room M4.
I prefer the way the university does it.