Nokia knows about power saving? Maybe on the S40's. The last Nokia that I owned that could last a night without a charge was the N95-8GB.

The N97 would last 8 hours with use and 12 without. The N900 - despite multiple new batteries/changed handsets and then tweaking of the power kernel - turning off vibrate etc got me around 3-5 hours with heavy use and 12 with little use. I know some people claim 48 hour use without charge but my experience with 'smartphones' and battery life remains negative. Not just nokia, same for HTC/Samsung.