I've been using Oh Life for a few weeks now with great success. It's very easy to use. They send you an email each evening (or whatever time you specify) that basically asks, "How'd your day go?" and you reply to the email. It then keeps everything in chronological order and you can log in any time to read past entries.
Today, I thought of putting a twist on it that some of you may find helpful in trying to achieve your fitness and diet goals (or any other goals for that matter.) In the spirit of Atul Gawande's awesome checklist article, I'm going to leave a checklist near my computer so I can respond to the following each day:
1.) What happened today?
2.) What did I eat?
3.) Did I work out? If so, how and for how long? If not, why?
5.) How much money did I spend today and on what?
6.) Any other specific questions about long-term goals or projects I'm working on
I think this will be a great way to kill several birds with one stone. Experts always say to journal about this or that to introspect, stay on target, stick to your diet, watch your spending, etc. Why not do it all at one time and in one place?