If it is within 30 minutes of going home or to lunch - any requested activities which may interfere with going home or going to lunch may be postponed until ones return simply by declaring the Glen Rule "In Effect". Doing this forces the requester to return after you are back from lunch or home and reduces the chance of you not being able to enjoy your time at lunch or home.
George - "I need help moving these boxes."
Mike - "Glen Rule, catch me tomorrow." (or after lunch)