depends who he is to you & how much you are wanting to spend.
For my boyfriend for xmas i have got him an ipod shuffle (which im putting his favourite songs onto), some DKNY be delicous for men which smells sooo nice! 2 cd's & a dvd boxset.
its my partner's son who will be 18 in 2 days time my partner is buying the present. lol the blow up doll is a gd idea i dont know how seb would be able to hand that to his son tho lol. He had thought of an ipod the same 1 as me the 80gb one but that is a small present to start with
Is he into gaming? Maybe a PSP or DS Lite?
i think the Ipod is a good idea though, but depends whether he likes music i suppose.
I think the idea above to get tickets to something is a great idea, maybe 2 tickets so he could take a friend.