I was just going to suggest a kiddizoom camera, we got our twins 2 of those for christmas and they still love them and take them everywhere.
Our boys also love lego, they started to get a bit sick of the lego duplo and wanted to move on to the more advanced stuff. Daddy has to help them with it, but it gives them hours of fun. But if your son has never really played with lego, maybe start him off with the easier stuff first. Or maybe playmobil? That's like the best stuff ever. What TV shows does he like? Gets DVD's and any toys. One of my sons loves fireman Sam, for his birthday last year we got him a fireman Sam scooter and dress up outfit, and he went as Sam for Halloween (his birthday falls on halloween). And then for Christmas we got him DVD's, a toy fire truck with figures and fireman sam PJ's, dressing gown and slippers. Books are good .. maybe walkie talkies? Our boys have walkie talkies that have a very good range. They get hours of fun out of them and their cousins love them too. Toy cars? Even stuff for his room.