My Fitness Pal.com keeps track of measurements, weight, calories and exercise. It's so easy to use and they have every food imaginable online with all the nutrient values.
When I did weight watchers one of the keys to success is tracking and I have to say I was not good at it. Writing things done is painful and time consuming, I'm a more online kind of girl, plus my phone is pretty much an appendage.
The thing I like about it, is it keeps you conscious of if you are having your daily allowance of sugars, fiber etc....I was shocked, first thing I have is coffee and I love the flavored coffeemate. I would use all my sugar for the day on 2 Tbs of creamer......so my goal is to somehow enjoy soy or milk again.....gonna be harder than given up wine!!