This works really well. My mom did this for me, and I had credit in the 700s right out the gate when I turned 18. They don't even need to give you the card; just add you as a user, shred "your" card, and then use and pay their card normally.
Exactly. There are groups of people who basically sell this as a service.
Its far less effective if you have negative marks though. Great for beginners.