hi jennifer ---
i babbled some in my thread, too, but i identify with what your trying to do and i'll be of as much help as i can.
its GREAT that youre walking 2 1/2 miles every morning. its a great start, easy on the knees, and if done at a high pace can be really good for the heart. it sounds like youre in phase I of your lifestyle change... i dont know how youre eating but be very careful of bad carbs---potatoes, white rice, bread, crackers -- anything that comes in a box. they contain a lot of trans fat/sodium and other additives that will only hinder you. also be careful or frozen entrees. while they have only a certain amount of calories, theyre also VERY high in sodium, too.
the best thing to do is to get reading! educated yourself on nutrition, on the ins and outs of fad diets, new discoveries on things like transfats, etcetcetc. simply *knowing* what i put in my body made me understand how to treat it better and how much more energy i could get out of it. also... i cant stress this enough but try only drinking WATER and only water, and LOTS of it!
now to your actual question and a timeline:
Sept. 1999// 205lbs-215lbs:
October 1999// 189lbs. - 192lbs.
December 1999// 179lbs-185lbs.
February-March 2000// 175lbs - FIRST PLATEU! i called this the plateu from **** because the scale just STOPPED moving. i conquered this by moving to the gym. i'd usually do 45-60 minutes walking at about 4.5 on the treadmill, on a 2.0 incline (i couldnt jog, yet LOL) an then id pick the "fat burner" option on a stationary or sit-down bike and peddle away for another 30 minutes.
June 2000// 170-173lbs. WHOO HOO.
September 2000// 165-168lbs. Second Plateu. I was stuck at 168 FOREVER! the weight really started coming off more slowly at this point. i began working a night job this september and the odd hours took some getting used to. i started drinking way too much coffee!
January 2001// 163lbs-165lbs
June 2001// 155lbs-158lbs... goal attained!!
I kept the weight off from June 2001 through the present, and continued to lose, but I've gradually added "bad" foods back into my diet because LIFE is LIVING

I weigh between 149-153lbs right now... I work out between 4-5 times a week. i do high impact step aerobics twice a wk, and jog about 2.5-3.5 miles 3 times a week, and do weights about twice (ive slacked big time on this though!)...
anyway, plateus WILL happen. because your body gets USED to the activity youre doing, the time you do it at, etcetcetc. even recently, i switched my jogging evenings to lunchtimes and i can already feel it tricking my body. the added bonus is that i dont over eat in the day...
but i do feel im at a plateu now, however, after reading an article on "extra skin" im wondering if this isnt what im experiencing. that part was probably the hardest for me and one of my biggest insecurity issues. everything sags, no matter how hard i combat it at the gym!! but the way i see it, everyone elses will start to do it soon too..... and ill still look good in my outfits! and FEEL good, too.
good luck
*melanie