20 Ways to Stick to Your Workout

http://www.active.com/fitness/Articles/20_Ways_to_Stick_to_Your_Workout.htm

OMG, I think #20 would definitely be motivation enough!

"20. Blackmail yourself
Take a picture of yourself shirtless, holding a sign that shows your e-mail address. Then e-mail it to a trusted but sadistic friend ..."

I think I'd have to add a #21: Get yourself a Sam Meemken. That worked really well for me! (I miss you Sam!)