Regarding my previous question on user activity, how long is the ideal amount of time to allow the computer to sit idly before considering the user to be away?
In my current application of this method, it is far better to receive a false negative ("user is not active"), than a false positive ("user is active"), so therefore a relatively shorter time will probably be better for my specific instance.
However, I'd like to see some input and justification for any definition of sufficient, concerning idle time with regards to general use.