fitness gurus: help me take the last step!!!!!

[Blue_Tires]

First of all, I wanted to thank the Lounge for the advice and support when I first started my efforts last August....To recap, I'm 28 (male), 6'2, and now 214 lbs (down from 251!)....I acheived this mainly from low-fat, low-cal diets, and running/waling on a treadmill or elliptical machine almost daily (now up to 3.25 mi)...At first my target was 220 lbs, and I thought it would be a miracle to ever reach it, but I think I have a real chance to get down to an even 200 (fwiw, i was about 185 in high school)...

My problem is I seem to have hit a wall...Even though I've increased distance on the treadmill, and added the occasional weightlifting session, my weight has been fluctuating daily between 214-219 for about 5 weeks now...Another problem is that even though I've lost a lot of weight, my gut still sticks out (A LOT)...I can feel it hardening, but there is still a kind of thick layer of fat around it, even though the rest of my body is pretty toned by now...

So what should I do?? What's needed to drop the last 15 lbs and get some photo-worthy abs in time for summer?? are there any tips, exercises, supplements or books that anyone cares to recommend?? thanks in advance