I never had a curfew. My mom's approach to parenting was the "off leash" method. No idea how I turned out so in touch and responsible.
ETA: Well no, I know how. If you've ever heard about kids who were abandoned and raised by wolves, I was raised by books. It was funny as hell when I saw Megamind, because I used to mispronounce big words I'd never heard out loud all the time. I used to think it was "bed raggled" instead of bedraggled.
I still have words that I know only by sight for exactly this reason.
I never had a real hard curfew growing up, as long as I told my parents where I was. From 10-11 onwards I lived in a small enough town that it didn't really matter- we didn't even have a bar or liquor store until after I had left for school. I also never really had set times devoted to studying or accomplishing most tasks, so I basically had to learn time management myself. My parents were, in general, pretty hands off. I went to a boarding school at 16, so I got used to life in dorms away from the folks and dealing with roommates before going off to college, and I think the combination of these has helped me adjust better than many peers to life outside my parents' house.