Re: do you inhale?
it also depends on HOW you're blowing your rings. the two methods i've heard of is when you 1. pop your jaw to cause the smoke in your mouth to be forced out 2. immitating a small "cough".
i personally use the second one, and that way i can start blowing rings when the smoke is weak at first ((it usually isn't for me though)) all the way through the cloudy smoke, to the weak smoke at the end. and because i'm making this "cough" motion with my throat, i don't really worry about having to exhale because the coughing gradually exhales some of the smoke