For my 14yr old son, it's a bit different. See, he had saved up a boat load of his money (from previous birthdays, Christmas and $$$ from mowing the lawn) and has bought a "project car". He has always been good with his hands and a very hard worker. The car does run--'88 Trans Am (daddy drives it now LOL) but still needs some work. So this year, he asked for car parts along with other stuff (he works on a model train also)
Car stuff....
T-top gaskets
Car Cover
Radio Installation kit
Stuff for the train....
Jimmy Johnson Boxcar
Jimy Johnson Expansion Set
Kasey Kahne Expansion Set
North Pole Christmas Set
Other stuff....
Call of Duty-Modern Warfare 2 for his PS3
Dirt 2 for his PS3
Hoodie
Winter gloves/hat
3 sets of pajamas
I also have an almost 13yr old son too. Here's what he's getting.....
Call of Duty-Modern Warfare 2 for his PS3
Rainbow 6 Vegas 2 for his PS3
Summer Sports for the Wii
Crossman Pellet Rifle with pellets
Some homemade movie that he saw on
Amazon 
A Camera case for his camcorder
A set of camcorder tapes
Diary of a Whimpy Kid 3 & 4
An MP4 player with a speaker case
Hoodie
Winter gloves/hat
3 sets of pajamas
They also both asked for a laptop, but that's not happening. LOL
But if he has a pay as you go phone, then maybe get him some minutes for it?
I know this age is so hard to buy for and I'm sure it'll get harder each year.