Thank you all for the great input !
Collin does have a twin sister and an older sister of 9.
After the post about LEGO trains I did a little research and wow how cool is that! The new (as of 2009) rail system is all plastic. The control is via infrared hand held that can control 4 trains. The motors, IR units, and remotes are fairly inexpensive, the trains are about the size of O scale, and the best part is no wiring worries!
I showed Collin a couple of video's on the net and he is hooked! He loves LEGO anyway and has a bunch of people, cars, trucks, cranes etc. Another great thing is the remotes, IR units, and motors can power anything if he gets bored with the trains.
We talked about it and he would like the LEGO train for himself and I think I will surprise him with a Loco and a few cars that he can run on my layout as well.
Thank you all for the help!