advice on using my Contact at accenture

Hi guys, I wanted to ask all of you for your advice on how to best approach this contact i have.

Through some volunteering i did when i was in high school, i met this guy, and talked to him now and then. I don't know him very well as he's much older than me, but my parents did talk to him about business a little bit. In addition, i never talked business with him as at the time, i was still a freshman/sophomore in high school and had no clue i'd go to business school.

Little did i know, he was/is a Partner at Accenture. I called him last spring to inquire his advice on majors i was considering, and he was very friendly about everything, but he also was very very busy, so i didn't have the opportunity to talk to him extensively.

I would really love to get an Accenture internship for my sophomore year summer. So my question to you guys is, How should i approach this situation.

I know he doesn't have time for emails, and i've talked to him over the phone a couple times, so it's a bit more personal than emailing. Should i ask him about his past, and about Accenture? I don't want to piss him off by asking for something, as i don't know him nearly well enough to ask for something like that, but he is the kind of person that i feel could help me out.

thanks for your responses.