If you're a member of a gym, you can often get your body fat percentage done for free. I've also got body fat scales. One thing to keep in mind is that it takes so so long to alter the number and it is quite possible that you have 10lb of flab, as you say, even at your goal weight. I know the last two times I've had my body fat percentage checked the ladys were very very suprised at mine. I think I'm leaner now, but it was 28%, even though I was 119lb at the time. If you check the BMI scale you'd see I'm on the low end, almost 'underweight', but I also have my fair share of extra handfuls that perhaps shouldn't be there.
The only thing we can really do about it is stop obsessing about the scale if you're at your goal weight, but use consistency with your eating, exercising and toning workouts. Even if you do 50 squats a day and 20 pushups, you'll see a big change in your jiggle-factor, only it's probably going to take 8 weeks of doing it before you notice.
--- Gen (5'3)
| current weight: 123.0