in reply to The most useless key on my keyboard is:
I used to work in an office where everybody had a terminal and only the gifted had PCs. Back then you actually needed a Scroll Lock when looking at some reports that would go on for pages and pages. Why it didn't die and actually followed onto the PC keyboard is a mystery to me.
An actual vote for how useless it is should be recorded by the manufacturers of KVM switches that use that key to activate the switch. If it is useless enough for them to hijack it, then it is really useless!