How do I know if the guy I met online is for real?

So I met this guy and he gave me his number. He seemed pretty cool so I started texting him. We've been texting for like a week now. He keeps asking to swap pics with me and I keep stalling cause I wonder what he really wants from this? Like does he really want to get to know me or just judge if I'm hot or not. He made an AIM account when I suggested he make it just so he could talk to me easier which I thought was pretty sweet. And I don't usually give my information to random people online so this is like a big deal for me you know. So I was busy all week and couldn't go online to talk to him until the weekend and so we planned to do it Sunday since he was busy Saturday. And then I asked him if he's given anyone else his number and he said "just 1 other, she's really cool from NC". And so I just kinda stopped talking to him cause I needed to think things over. Then yesterday his schedule cleared and he texted that he was online and we could talk. Does this mean he's really interested in me or just really eager to see my face? And what does he want out of this?

I haven't met this guy in person.
I don't plan on meeting him in person. He's in a different state then me anyway.