I read a battery guide the other day that the biggest "threat" to li-ion batteries is actually heat. All batteries eventually die off, but li-ion ones are apparently highly susceptible to heat, which greatly accelerates the rate of "decay" of the battery ... so the iphone, which already has crap battery life, also generates a lot of heat, which further rapes the battery ... it's a vicious cycle!

@ndri11 >> 1.5days is actually pretty good. On work days (i.e. I don't use the phone except for calls & sms) a full day takes about 70-80% of the battery life.

On weekends sometimes I'll be out of battery even before dinnertime.