I am of the belief that all kids should have a Christmas tree in their room (as long as it's safe, high enough not to be reached, etc!) :)
This year I got Landon a little 3' tree from Hobby Lobby and put it on his side table by the glider. I didn't do too much with decorating, his room has a lot of turquoise accents so I used some blue and turquoise decorations I already had. Eventually he will have a whole tree of ornaments we've given him.
I got some little initial ornaments from Wal-Mart for $0.99 to put his "monogram" on front.
I wish I could leave his Christmas tree up all year long ;-)