I lost 30 pounds between october of last year and about march of this year. The first 15 came off after I got a kidney stone and my doc said I needed to drink more water, so I stopped drinking pop completely. Just cutting the pop out of my diet made me lose 2 pounds a week for almost 8 weeks! The loss stopped just before christmas, so after the new year, I started eating better and exercizing every day. I lost another 15 pounds between the middle of January and the middle of March. Since then my weight has fluctuated about 5 pounds, but I haven't tipped back over 155 yet. I'd like to lose about 25 more pounds to get back to my high school weight.
One thing I found worked for me was writing down everything I ate. If you write it down, you are holding yourself accountable, and you'll find you eat less.
I found a really great website if you're interested. It's got a food journal that tracks any and every nutrient and has thousands of foods stored in it, an exercise database that tracks your calories burned, articles, a great message board, etc. It's better than any website I've every seen for diet and exercise, and the best part is that it's totally free! I've talked to several people that swear it's better than any site they've ever used, even the ones that charge a fee.
It's www.sparkpeople.com. If you decide to sign up, I'd appreciate if you'd use me as a referral (user name is shenanigan) It doesn't get me anything but points, which aren't good for anything really (no prizes or anything), but it lets me see how many people have signed up thru me.
They also apparently have a sister site you can use if you're pregnant. They won't even let you sign up for sparkpeople if you're pregnant, they refer you to the other site (which is also free).
Hope that helps! Good luck!
S.