Similarly - "the talk" my dad gave me happened one day when I was out warming up the car to go meet a girl I was seeing. My dad came out, sat down in the car. He said "Don't get yourself in trouble. You know what I mean." In fact I did know what he meant, so mission accomplished.
With the daughter, it was a little different. With the internet there really wasn't much purpose for a "birds and bees" level talk - she'd already been exposed to so much online without ever trying. My talk with her was more focused on:
1) NEVER, EVER share naked/sexual photos or videos of yourself online. No matter how much he says he loves you, or how strongly he promises that no one else will ever see them. a) he's lying and b) they never go away - they're out there forever.
2) Don't get pregnant until you're well out of college - it will screw up the rest of your life, and limit your future success. You'll be poor and miserable, and probably resent the kid because of it.
She seemed pretty receptive to the discussion and went on birth control before she went off to college.