...Advice for first-timers: Do not sit in front of the computer the whole time. That will exhaust you. Get up, walk around, do stretches! Stay active. Have other people stay up with you in shifts, if you can. Play music. Keeping your brain and body active will get you through this.
Man, I wish I could be with first-timer slipjig through this. I like to taunt the newbies - "You thought this was easy, huh?" That, and I could bite him to keep him awake.
I need a Blogathon icon!
EDIT: And at about Hour 18, you're going to be wishing I had a webcam, I tell you what. *nod*