So far today I have 43 minutes of usage (just listening to music) and 93% battery life remaining. Thats with EQ set to flat, 3G/WiFI/Bluetooth/Location Services off and EDGE on. No SSH, no Winterboard, just iBlacklist and Status Notifier.
kool kool... Right before i went to bed last night i was fully charged.. had music on all night till i woke up (about 10 hours) and my battery life looked like it was around 50-60% since it showed half the bar
I'm not sure that setting your EQ to flat will enhance battery life, probably quite the opposite. Turning it off will extend battery life, and improve the sound quality