Body Fat Percentage - images by the number
I like using Body Fat Percentage better than BMI as a measure of overall health-fitness-lifestyle.
BMI is an impersonal formula, and doesn't account for bone size/density, nor for muscle vs fat; it treats all people weighing the same weight as the same. In reality this is true, since it was created for (and named for) measuring "body mass", and not "body fat." But it's still disheartening for someone in good shape to hear they're overweight or obese..
Body fat, on the other hand, is just that - how much pure fat is your body storing, as a percentage of your entire body? People in good shape have a smaller percentage of body fat. People trying to lose weight are actually trying to lose fat, which reduces their body fat percentage. (and for 99 out of 100 people, their BMI as well.)
Unfortunately, measuring body fat percentage is a little tricky. There are several methods for doing so, with varying degrees of accuracy, price, and simplicity. And it's not something most of us can do at home.
Marc Perry put together a photo collage of men and women with varying percentages of body fat in his post "Body Fat Percentage Pictures of Men and Women." (click through for more images and detailed descriptions.)
Body Fat Images of Men
Body Fat Images of Women
These are perfect - now you can estimate, with your own eyes, what your approximate body fat percentage is. And it might even help you with setting and adjusting your goals as you move forward.
More info on body fat percentage and BMI, from Wikipedia.