I quit several weeks ago and my motivation is the "Quit meter" I got from this site;
http://www.silkquit.org/sqmmiv/meter.aspx
It keeps track of how long you've been smoke free down to the second, how many cigarettes you've been able to avoid, how much money saved and how much longer you'll live.
I actually look forward to seeing it on my PC at work and looking over my progress!
If you've just put em down or even thinking about quitting, get this program.