I can't tell your from personal experience yet b/c I'm only pregnant with my first but my mom was almost identical to your best friend. She had a quick delivery with my older sister only in labor approximately 6 hours and that was from the time she first felt any contractions. She said she waited a little too long to go to the hospital but by the time she get there was at about a 5 and then within an hour it was time to push. With me she started having contractions, couldn't get ahold of my dad (before cell phones), he was shopping for Valentines Day gifts. When he finally got home, she told him they had to go now. It was about a 30 min drive to the hospital, they got her upstairs in a room, she told my dad that I was coming. He went in the hall grabbed the first person he saw, she came lifted the sheet and I was crowing. They wheeled my mom to the delivery room and about 2 pushes later I was there. The whole ordeal was about 4 hours long. There was no time with either of us for her to have any drugs and my dad actually missed both births b/c he was putting his gown on both times. Her doctor told her if she had another she might need to spend the last month in the hospital parking lot!
I know that's probably not the story you wanted to hear, but from everything i've heard the 2nd one usually does come faster. How fast? Only God knows that. I'd just say have your bags packed, accomodations made for your son, and if you start suspecting something is going on just go to L&D and get checked out. The worst they can do is send you home!