what sort of things to get a 17 year old girl for christmas?

It depends on how much you want to spend and what her hobbies/likes are. Here are some ideas:

*Makeup - makeup, make up brushes, make up bag
*Clothing
*Tickets - movie, concert, sport event
*Technology - phone,camera, Ipod, computer, head phones
*Winter gear - mittens, hat, scarf
*Nail polish
*Purses
*If she likes art, get art supplies - canvases, paint, brushes,
*If she has a favorite show, get her something related to that
*Lotion
*Nice shampoo/condition
*Bath salt, bubble bath, body wash
*Necklaces/bracelet/earring
*CD or DVD
*Giftcard

Make up & gift cards to stores she likes to shop in. Phone case.

Jewelry, car. Trip to Europe. Gift card from Nordstrom's or Forever 21 or both.

A subscription to Scientific American, Foreign Affairs, or Vital Speeches of the Day

A savings bond account at the US Treasury Web site.

Movie tickets, Concert tickets, Hockey tickets.