website recommendation for people trying to manage their weight

My Fitness Pal isn't trying to sell you sell you a diet plan or particular food. It simply works out how much food you need to survive and then takes calories off if you want to lose weight or adds them on if you want to put weight on. 

Then you just log everything you eat and drink to make sure you stay in your goal for the day. If you exerise, you get to eat those calories too. I love it. 

It also has mobile apps so you can keep track while away from the computer. At the moment I'm helping to trial the blackberry version and its given me a real kick up the bum. Since the weekend, I've lost 6lb and it's only Thursday!