I got a new mobile phone on Friday:
a Sony Ericsson V630i. It had an overnight charge on Friday night, and was actually unplugged at about half past seven on Saturday morning.
It's been subjected to "normal" use since then, or at least whatever constitutes normal in my case.
It turned itself off with a flat battery at about half past four. I don't know how much of that time will have been spent talking, texting, taking photos and generally making agressive attacks on its battery life, but it will have been fairly typical of my general usage patterns for this sort of device.
So that's about 105 hours. Four days and a bit left over -- not quite enough to last until the evening of the fifth day before I have to plug it in.