I never focus on fat grams except for things like, "are my fat calories coming from monounsaturated or polyunsaturated fats vs. saturated?" Consuming healthy fats is critical in keeping your body healthy because they are a key place to get omega-3 fatty acids. don't even get me started on how important i think omega-3s are. they're good for your heart, they're good for your joints, they're good for keeping you full. there's more reasons, i wrote a paper on them (i'm a university student) if you're interested

it's a little nerdy.
if i were you, i would look at counting calories, a great site for that is
http://www.fitday.com. it also counts grams of fat.
one more thing; sorry, this is turning into a book...is a lot of low-fat foods are higher in carbohydrates or sugar to compensate for their lower fat content. to me, more importantly than counting fat or carbohydrates is reading labels and knowing what i'm putting into my body.
whew.