I decided to change my calorie limits a few weeks ago and it's been working really well for me. I joined fitocracy and have been working out with my friends a lot more/harder but I was always starving at the end of the day with an hour+ workout and 1500 calories. I kept going over--was still losing but feeling guilty all the time. So I upped my calorie limit to 1800 on hard workout days, 1650 on light or cardio days, and 1500 on no exercise days. I still get at least a 1 lb. loss each week but no longer beat myself up.
I also try to work out 6 days a week, but only 2-3 are my intense days. I'm sure I could lose more weight faster with a lower calorie limit, which is what a friend of mine is doing--1200-1300 a day. I really like how my new plan is working for me though. I also started following Alton Brown's list
here, except I only eat 2 servings of oily fish a week.