To get him to send you an email, either get the little girls to ask (which I don't recommend) or use their account to send him a message and get him to email you that way. Maybe ask for a pic or some other reason for an email. Just my suggestion.
Also (I am not an AOL user so this is just a guess) most messenging systems maintain a log, if you can find it it may log ip addresses as well as user names, especially in file transfers. Or a packet sniffer may give you some ideas, but that will probably just be the messenger server, but may be worth a try.
If he is only online for a few seconds I would think he is going into "invisible" mode instead of getting offline. He would appear as offline that way, but could still use messenger. Next time you see him online then off message him and see if he answers.
dAggressor's 2cents
