How to get his phone number?

I would say a little conversation prior would be good. If you don't talk too much, I'd work on that first. Become friends with him first, and then worry about phone numbers. If you are friends, it'll be easier to ask for/exchange numbers. Maybe add him on your myspace/facebook and send him your phone number. If he calls, then you know he's into you. Rejection is a part of the dating game, it happens to everyone and it does suck, but you have to get over it.
Personaly, I don't give out my number too often. I have to be single for awhile, and meet a girl who really stands out. Good luck.

If you don't want rejection, then welcome to a guy's world. At the end of a conversation just ask him if he wants to talk some time over instant messenger or the phone.

Why not.just ASK FOR IT? Naturally give him yours at the same time. You're not asking him to elope with you! What's the problem? Who cares about the friends really?

okay I've done this before.
If you have a calculator then type in your number
haha


or say can I have your digits? I'd like to continue this convo sometime (well get a convo started with him)) if you don't think there is much to talk about.then get his number and leave

I hate rejection too but if you want something really bad, you have to work your courage and go for it. Just ask for his number and tell him that you would like to text him sometime to see how he is doing. Guys loves get texts from girls because it makes them feel that they are attractive and want. Or just give him your number and if he calls that good but if he doesn't call then at least you try.