Mani or pedi from a local beauty salon.

If they have phones, new cases or accessories.

Perfume.

Pamper pack - latest girly DVD, chocolate, face masks.

Giving them an experience that they would have locally - like horse trail riding.

I've just had this conversation about my 13 yo boy cousin. His mum said vouchers for iTunes, EB games, or comedy or documentary DVDs. But vouchers were the emphasis.