Yesterday I took my phone off the charger at 9:30 AM and had an above average phone usage day.
I took 4 phone calls, with total talk time of about 1 hour. Searched the web while cooking for a recipe ingredient, used google goggles to help me look up a product, took 6 photos at a grade school fund raiser, showed the photos on the phone to my wife, read a few facebook updates, and checked and managed my gmail a few times because I was away from my computer a bunch. Plus, I use live wallpaper.
At midnight I thought of this thread so I checked my battery before I plugged it in for the night and I was at 65%.
Those that are getting 4 hours must have unrooted phones with 4g data and gps turned on constantly with twitter, mail, and facebook updated automatically every minute while texting and/or talking on the phone constantly.