i only smoke pot these days, so it' not hidden, but i do keep it out of sight.
i live w/ my gf. she knows i smoke, but neither of us want to worry about anybody who might stop by un-announced (we rent, both our parents live nearby, etc.). there's one room in our house that i have as my "office" where i smoke and keep all my things . . i don't like to leave anything out in the open, so bongs are in a cabinet, and bowls/bud stay in drawers.
honestly though, even when i was living with other smokers, i didn't like to leave my things lying around. one of my big things about being ok with my own use is that it doesn't interfere in my relationships with people who don't smoke. so i won't lie about the fact that i love pot, but i also don't want my living space (or clothing/appearance/etc.) to advertise it.