When you feel your motivation waning, go clothes shopping. You'll either be pleasantly surprised at what size you fit into, or you will see how far you still have to go to reach your goals. A little reality check, either positive or negative, can be a good thing and really keep you motivated.
When you're craving something that you know isn't on your healthful eating plan, don't deny yourself! It's been proven that just three normal bites of what you are craving can satisfy your craving. You don't have to eat the whole candy bar, piece of pie, cake or dessert.-same goes for any food.
Nothing motivates me more than to listen to a great audio book. It makes you want to keep going if you are at a climactic part or keeps you coming back day after day to see what is going to happen next. I set my treadmill or recumbent at the intensity I'm aiming for that day and go for it!