yeah, we just have the itouch, but I think it's life is similar to a laptop--ours seems to get maybe 3 hours? Dh usually sincs it with itunes on the comp and charges it at the same time... and usually every night
I have the 3GS which is supposed to have I think 20% better battery life than the earlier iPhones. I only charge mine every couple days and that's with using the internet on it pretty much every day. I do notice if I use the internet a lot I have to charge it more but usually not every day. I've used it to watch tv and movies on plane rides and it was fine for that too.