Blackberry vs iphone, which battery last longer?

I have a blackberry curve 9300 and a iphone 3g. I'm kind of getting sick of blackberries and want to try my iphone out, but will an iphone 3g last longer then the blackberry? I was going to use it for txting, twitter, fb, instagram and maybe msn once a week or so. How long does a iphone usually last with these apps running all day? Or is there ways to use these in a smart way but keep battery drainage minimal

Iphone

8 hrs. The Z10 can last 10 hrs running those apps, the Z30 24hrs at most.