Just like the drunk drying out or the heroin addict getting clean. It sucks until it doesn't. There is no sugar coating it.
What you can do is drink lots of water. Exercise/run - stay active.
Cut your normal caffeine intake in at least half, and eliminate alcohol.
Check into this site as often as you can. Read, read, read.
Collect digits, and call or text somebody. I'm sending my digits via PM right now.
Most of all - refuse to cave. Refuse to be nicotine's bitch. Refuse to be a slave to a dirty, rotten weed.
When all else fails, slam your nuts in a desk drawer - that'll take your mind off dip.