Visited the Apple store last night. The gentleman that helped me out did a Apple Sotwear check on my iPhone and founded out that my battery shows no know issues. Interestily, the diagnostic showed that I had 8:10 minutes of usage and 1 day and 17 hours of standby; however, my phone showed that it had been used for 4:37 minutes and standby was 1 day and 17 hours, very strange result (I wonder if the iOS is NOT showing usage as it should). He also told me that no one needs to worry about calibrating the battery, I DONOT beilve on this, as Apple recommends on its website. As far I'm concern, batteries need to be calibrate, but I'm open to learn otherwise. Anyhow, the diagnostic also showed that MOBILEME and PayPal apps were quitting unexpected. I did notice PayPal quitting, but not MobileMe; however, I cannot get emails or notifications via push, I need to go into the mail app and refresh it in order to receive messages.
Anyways, he said the samething already posted on this discussion, turn off locations and things that's is not necessary. Also, the technician suggested that it might be a glitchy in this new iOS; however, he was blaming apps for it, when on my case only one developer app showed problem, PayPal (which I deleted) and Apple's MobileMe.
Currently, my usage is 5:53 hours and standby 1 day and 19 hours. Much better then my first usage. Apparently, the battery can improve overtime. And if Apple fix this "glitch" we will experience much better results with this new iPhone and iOS.
Hope it helps.