Anyway, I don't want to go derail this topic with what I approve of and what I don't, because that could get quite long-winded. :P
I think, up 'til at least 16, yes, the parents should know where the kid is going, and who they're going to be with. I never had to be asked to tell that information. Heck, I'm 20 years old, and I live away from the house, and I still tell my mom, "Hey, going out to a bar, probably going to come back a bit tipsy." :P But, I think once you hit that age of having a car, you should be granted a bit more freedoms with that. 16 isn't 2, and it's 16 for a reason.
Having a cell phone, having a credit card, having a car, those are all things that in a metropolitan city most people don't deserve until they are a bit older. I dunno, maybe that's just because it's what I'm used to. If my situation were different I may agree with most saying that 11-13 is the perfect time for a cell phone.
Having a mobile phone just seems like quite an adult thing for me, so I don't feel it's something that non-adults should have.
That being said, when I was younger (when I was in high school) my family had ONE cell phone (like I said, I grew up with them being a bit newer). Whenever someone went out (mom to the grocery store, me to the movies, etc.) that person would take the phone. So although I did not have a personal phone, I did sometimes have use of one. Not sure how well that would work nowadays though, and when I have kids it may be commonplace to have a cell phone in their pacifier!