Well, I've personally decided that the excuse "but I have two young kids" will no longer cut it with regards to diet and exercise.
I just signed up for a sprint distance triathlon taking place on father's day this year, and I hope to use that to jump-start my fitness program.  Goals are always a good thing.
Medium term goal:  Lose enough weight to get off my blood pressure and cholesterol medicine.  I think it will take about 30 pounds.  I should probably join Martin's challenge in another thread.