Okay, so you might think I am completely mad here, but hey, I am willing to risk it.
I have a real hard time with my motivation to exercise at the moment. I had suffered depression during the last twelve months and everything seemed to go "to pot".
I read a thread about the website "Flylady.net" and had their book on how to organise household chores. So now I am using the same method for exercise.
You use a card box and cards with index cards as separators. I have my index cards numbered 1-28 only at the moment because I am trying to look at my diet as 28 days at a time. then on cards I write down something I intend to do towards my fitness goals (a 35 minute exercise video on one card, a 10 minute yoga workout on another, a 1 hour walk on another). I use white cards for the things I want to do everyday and coloured cards for, say, blue for three times per week, pink for once a week etc. Some things are not exercise, like, listening to a relaxation tape, etc. but things that I just never get around to doing for myself. Hey, you could even have one just for say, painting your toenails, whatever it is that would make you feel better if only you could get around to doing it.
Okay, so then I put the every day card in front of the next day and slot the others into certain days for the next week. On top of the card you put how long it is (i.e. 10 minutes, half an hour, one hour, etc etc). Then when you have time in the day you just pull a card out depending on how much time you have and do whatever it says on the card.
Sometimes when you are feeling low it is difficult to remember/motivate yourself to stick to your goals. I just find this method helps because then I don't have to think about it. I just pick a card out and do it. And usually when I have I feel so much better!