Some years ago I was on Weight Watchers, lost almost 50 lbs and maintained for 4+ years. Then the stress followed by the pounds slowly piled on.
I have joined a diabetes prevention program through my job: it's very similar to SparkPeople and Weight Watchers in that you set goals, then measure and track your food intake, exercise levels, and emotional issues. Meeting with people face-to-face once a week is good, but I find the online community to be super-helpful (and friendly) as well. I have re-started my efforts to track on SparkPeople and look forward to engaging with the community. :-)