I've got two steps figured out so far:
1. Eat crap less often, and less of it when I do. With Mrs. Penguin off in the wilderness and me by myself, I've found I eat a lot of convenience foods: frozen pizza, pierogies, etc. (edit: and not much in the way of fresh vegetables, hence Mrs. Penguin's insistence that I eat more salad)
2. Actually go to my martial arts practices more often, or when I've got a conflict with something else that I can't get out of, practice at home when I have time. I have decided that I owe myself four hours of martial arts every week, even if I can't go to four hours of practice.
I'll see how far that gets me. If I need more, I'll start looking around for ideas.
iPhone App: Lose It. (Its Free)
Accurately track all intakes and exercise.