I have 450 and on average use about 175-200min/mo. Mostly it's my mom calling me to just talk or my sister calling to tell me everything i couldn't care less about that's going on in the many facets of her life in SD.
When I actually make a call (very rarely do) its either: important or I'm drunk
yeah, I forgot to mention the drunk dialing... I don't do as much of that as I used to though