It'd be kinda cool if he still lived there. I got a letter forwarded to me from my best friend back in 1st grade last month and it's been kinda cool to see how he's doing and how much he's changed and to know who ended up doing drugs, who's pregnant, who's a potty mouth, who's gunna end up being a super senior....
Ah... you don't know if they've moved or anything... still, it could be worth a try... just make sure you tell them who you are, so they don't think you're some creepy pedophile or something! XD