You've spent months, weeks... even years admiring him and now its crunch time. You know where he hangs, so be there. Pump up your presence in his life. You probably also know what he likes: sports, music etc. and that gives you a subject to strike up a conversation with him. Chat with him a few times to get him comfortable with talking to you.
(Proceed to Popping the Question)

You want to go to prom, but don't have a boyfriend but have plenty of friends that are boys.

A guy pal is a guaranteed good time because you already know he's someone you can talk to and he's easy to get along with. Pick your favorite bud and ask him.
(Proceed to Popping the Question)

If you don't have your eye on a dream date, rally the troops. Chances are, you have plenty of friends in the same boat. You could get an even mix of guys and girls or just go with the chicks.

You know there will be guys at prom that are flying solo, and when they get out of their T-shirts and jeans and into a tux, they're going to look so amazing, soon you'll think "Wow, I never noticed him before."

Remember, prom is about hanging with your friends and celebrating the ending of the school year, so don't stress about the romance aspect and just have a good, but safe time.

You can do this in person, on the phone, a text message, an e-mail or in a note:

You might say: "I was thinking it would be fun to hit the prom together, if you don't have a date already. What do you think?"

Or

"Do you have any plans for prom yet?" And if he says he doesn't, continue with, "How about going with me?"

Just remember when asking him, do it in private, make it fun with no pressure and give him time to answer.