oh ok.
i'd get him a lower end william henry
http://www.knifeworks.com/index.asp?PageAction=VIEWPROD&ProdID=5771
or the Case tiny trapper or mid-folding hunter
http://www.newgraham.com/case_caribbean_blue.htm
basically something that looks like a pocketknife, so that other kids and their moms won't freak out. if you get him something that looks tactical (ie a benchmade), he's going to link it to the TV and movies he watches and start thinking of it as a weapon, mall ninja style, and might injure himself and other kids. So you want something more traditional, outdoorsman/davey crocket style so that he considers it a cool toy for the outdoors or just whitting wood in the backyard, not something to settle disputes with.
but you also want something of good quality that's not cheap. If he happens to keep it till adulthood, and it lasts that long, then it becomes something special to him, almost heirloom-style, and I think that will mean a lot to you in time, if it happens.
give him a cheap knife, and if he gets into the hobby, he's gonna realize you started him off on a P.O.S

and if he doesn't get into knives, hey you just got yourself a free knife.