Went 19.5 hours yesterday before I plugged my phone in and had 36% battery left. That's with over an hour of phone calls, an hour of web surfing, 20+ texts,3 email accounts set to 5 min. Wifi, GPS always on, backround data everything, i literally do nothing to save battery. It was a light usage day with good signal.
From my calculations from when I leave my phone off the charger while i sleep in on weekends if I did NOTHING on my phone from 100%-0% it would last a minimum of 80 hours. Thats with EVERYTHING turned on but NOTHING happening no incoming calls etc.
Other than rogue apps or defects in your phone signal strength is by far the biggest factor in battery life. If you have a solid signal all day it will double your battery life. Get a airplane mode switch and if you know you are going to be without a signal for an extended period turn it on. I wonder how long this thing could go in airplane mode? I bet it would be crazy.
I recommend "switchpro widget" it has all the switches possible and you can customise them in any way I have ten switches in a 1x4 space on my home screen. Even has a task killer and a battery guage with % that goes into usage stats when you hit it, you will never need to go into settings agaoin.