i fully charge my phone before i go to bed. i leave the wi-fi and sync on overnight. when i wake up (about 8 hours later), the battery loses a bar. (with no use while sleeping)
i turned off task killer last night. fully charged my phone and went to bed. when i woke up the next morning, the power was still 100%. it's now 12+ hours since i fully charged it and it's still at full bars. (with no use so far).