In today's world, I think a 19-yr old should learn how to manage money with a credit card, learn how not to carry a balance, how to budget, and learn how to never spend beyond his means. There are many of us who use credit cards for the rewards programs (for example, we get a percentage off gas and groceries) and NEVER carry a balance.
Used properly, credit cards can save lots of money. Used irresponsibly, they can be a disaster.