How about some sort of combination system? Maybe some low-power lights (e.g. the little 9W fluorescents) to provide a minimum level of constant illumination and larger lights which come on on buttons or sensors.
I wish we could get government buildings to adopt the same principle though. They're the ones who are always telling us about having to save energy, yet every govt. building I go into has just about all the lights blazing away even in broad daylight.
