Heh, looks like the month is almost up already, but whatever:
You can do crunches or sit-ups till the cows come home, but you'll never see any of the abdominal muscles if they are covered with a layer of fat. Even if you're not going for a full on six pack, to be "toned" you'll need to lower your bodyfat %.
AS WELL as doing the correct ab exercise to increase the passive contraction, etc.
Basically, eat well, and do cardio: e.g. run, swim, bike, whatever.
PS - If you really want to lower bodyfat fast, it's better to go high intensity even at the expense of length of workout, ie do sprint intervals instead of slow jogging. Search google for "high intensity interval training" for more info.