Here's a quick one...

A joke about a conversation between two geeks
— "When you look at a girl, what do you notice first?"
— "Her hair, then her eyes, then her nose, then her lips — I have dial-up."

I was going to write a full post on presentation skills today but couldn't find the time coz I'm reading Surely You're Joking...right now, so expect it in 1-2 days.