Overprotective Parents?

I'm 23 years old and am working, saving up money, trying to move out of my parent's house. They've always told me that it doesn't matter if I'm 30 and living with them - they would still worry about me. Here are some examples of what I deal with: I can't go for a walk in the woods w/out them calling me every 2 hours. I am forbidden to walk in the neighborhood alone at night (even tho there is no crime or violence). If I go to a friend's house they want all information. If I go out somewhere they call me when it gets dark and ask where I am...if I'm at a park they tell me it's time to go. This isn't the half of it. I've tried talking to them but they think it's normal to be so protective. I also want to mention that I'm not irresponsible for my age. I work, attend university, and manage my own bills. But I feel like a child. How can I grow when they won't let me? I'm getting tired of being treated like a grade schooler. Someone please give me some suggestions before I scream!