SG - after losing a significant amount of weight the body adjusts to the workout and routine you've built and it will plateau. the body tries to hold onto the extra weight so you have to do what you did to lose the initial weight - stun your body. you have to hit it with a new workout routine that will prevent you from going through the motions basically relying on muscle memory. The good news is that you don't necessarily have to exercise any harder, just differently. a new exercise routine should really trigger new weight loss/muscle growth.
also, don't forget that at some point it will seem like you aren't losing weight/size because your muscles are really getting bigger and stronger and they weigh more than fat.
i really, really, reallyreallyreally recommend
The Abs Diet books from Men's Health magazine. It isn't really a diet so much as a book or ideas and recipes. YUMMY recipes in fact.
http://amazon.com/s/ref=nb_ss_gw/103...s=the+abs+diet