There's a sort of game I play with my phone, where I see how long it can last between charges. Although I have a moderately powerful Motorola that's more a mobile computing device than telephone, texting, telephony and occasionally looking up the weather forecast are the most demanding things it does - most of the time.
So it's normally run with 3G only, no wireless, and GPS off permanently too. I found leaving each of those on, even when not being used would drain the battery about a day sooner than otherwise. Battery life can be a lottery anyway, depending on where I go and whether the phone comes too, plus the local network (O2) is in and out like a fiddlers elbow, and having the phone hunt for a signal kills it faster than anything except route navigation using full GPS and wireless.
So I play the game.
A few minutes ago the phone just bleated at me - 4% charge remaining after 5 days, 4 hours and a few minutes. I've done some texting, made a few calls, taken a picture and checked the weather a couple of times a day - not heavy use by any means, but not bad at all, and pretty much as good as the best I had from my HTC desire.