If discretion is what you're after, the pipe has the bong beaten. The only time I can safely use my bong is in college - definitely not at home. With a bong, there's the process of taking it from whatever hiding place you have, loading it up with water, worrying about the bowl and female piece for transportation, and the conspicuous act of actually hitting the bong. Smaller pipes can be transported easily and eliminate many of the problems that come with bongs.