This is the biggest battery offender, next to games. GAMES can use your battery up in as little as 2 hours...OUCH.
After 3.1 upgrade I decided to disable PUSH .. and viola .. battery lasts well over 1.5 days of nominal use. If I play games, I just make sure to charge overnight or during the workday to get back to FULL.
My Problem has been solved... at least it seems so far. I noticed my phone had 12 TCP connections to my company's Exchange server so I removed the Exchange Account and re-added it. (Since I am the Exchange Admin at my company I also deleted any iphone associations with my Domain Account, this may not be a luxury most have) Now I only have 2-3 and my battery drains about 5% per 1 - 1.5hr on Standby with a couple texts in between. Can anyone else verify that their phone gets significantly improved battery life with push disabled?