Where is the 'Any Key' on a Keyboard?

Sometimes during software installation or hardware configuration, a computer user is asked to "press any key to continue". The misinterpretation of this instruction has become a great joke amongst the computer-savvy. Techies love to imagine a user searching their keyboard for the "any key". There are a few keys on the keyboard that no one seems to use like "scroll lock" so the presence of an "any key" seems at least remotely plausible. The user searches around, checking each key twice, but when they come up empty handed, they call tech-support and ask "where is the any key?" While such a call has undoubtedly occured, its hopefully not too common!