At the age of 19, I moved out of my parents' house, then got my first car, then got my first cellphone, all in the same month. A cellphone is a waste of money unless you need it for work, or you no longer live with your parents. Then again, that's just me being bitter because the only people who call me are my parents (my job doesn't really require a cell phone).
I've had my own room since I was 10. Having your own room is practical for many things, like arranging stuff however you want, and watching TV/playing games late at night/early in the morning without having to worry about waking someone up.