Here's another thought....replace some of that cardio with weight resistance training. Cardio is great for the cardiovascular system, but it doesn't do a whole lot for toning your body. Weights can do that. You may find that with working with weights that you don't need to lose any more weight (and can possibly even carry a few more pounds!) to be a smaller size than you are now.
As Paleoanth mentioned, you don't want to get your body fat percentage too low as this is generally not a healthy condition for most women.
Another possibility is that some women have a genetic predisposition to carry some weight in their belly no matter how thin they get or how much they exercise. It's just how they happen to be built.
BTW, a 27" waist on someone who is 5' 9" is not fat by any standard that I'm aware of except possibly a very unrealistic one.

lol, I am in the entertainment industry, er, and 20 as well. but I just turned 20 so I still tell people I am 19...
ha, no one knows who I am anyway so I can reveal my secrets ;P
someone who is 140 pounds and is 5'9 can easily lose 10 pounds and not be unhealthy. but I do not think pitt is trying to starve her way to some unhealthy oblivion or troll us you all.
if this individual is anything like me, (I am 5 feet and 10 inches, 137 pounds atm) he/she could have concentrated fat, like in the waist or hips or thighs. I am by no means a professional, but I think exercise will bring off weight, eventually.
I firmly beleive in Low Carbing your way through life, but even though I follow the Atkins ideal, I am still open to the idea that a low carb and low fat is an alternative to a low carb and high fat. I would be interested in knowing the results you get Pitt because I am in that healthy body limit range too.
lately I have been studying about the combination of Protein, Fat and Carbohydrates. I have been looking for a secret formula, not really so much to lose weight, but to completely tone my body. I am shooting for low body fat. To do that, diet is essential. But so far, all I've managed to do is discover pilates, cardio, swimming and LCing :/
Oh well, everyone is different so that is something I think I will have to discover on my own.
Overall, I know limiting carb intake is the right path, and constant exercise is good. Maybe consider working out in the gym more. Actually, just move there
...just a little joke, that
actually, you may need to work out furitively everyday. I don't ahve anything to do but go to the gym and trainers and read mssg boards until my job starts again -_- so I can afford the time to do nothing but work out. It really pays off though.

Hi Lisa, I don't think it's unreasonable to have a 27" waist and want it to be a little smaller .. that's where I am right now actually. Although I don't think it can be done in two weeks, at least not in a healthy way. At that point when one is already at a sensible weight and wants to tone up one's shape, it just doesn't happen fast.

That depends on the person and their body build. I'm 5' 3" and even when I weighed 112 pounds in high school and was into a different sport every season (track, tennis, swimming, softball), I had a 29 inch waist (BTW, my face looked gaunt at that weight). I'm just not built to have an hourglass figure and trying to get to a smaller waist size would have been unhealthy for me because I would have had to starve myself well below my ideal weight and body fat percentage to get it. OTOH, my mother was 5' 6" and had a 24 inch waist in college. *Shrug*...we're all built differently.
*Wanting* a smaller waist size is one thing. Trying to force your body into it when you're not built that way because somebody *says* you should be smaller is quite another. IMHO, fashion industry "ideals" are far from healthy and often unrealistic. I think if more women realized how many of those photos of models are airbrushed and touched up, they'd stop starving themselves to make themselves look like something that doesn't even exist in reality for the majority of healthy women.

pitt,
Your going to have to have strength training and intense isolated abdominal training. That's the only thing that works for me......cardio does nothing but burn calories IMHO. You've got to add muscle and the only way to do that is weight train.