battery life

hi! this is my first post from my ibook heheh i'm a mac newbie and i have to say its hard to get used to it, but i woun't give up so easly i have to say its really nice osx and the ibook.
my question is to the new ibook users, the specs says it has 6 hours battery life but when i connect it it doens't go to 6 hours... how much time can you keep it on ?

I get 4 hours, 20 minutes..@ 60% screen brightness... You only get the 6 hours if your screen brightness is set to minmum and you are not using the hard drive/CD drive all the time.

Generally, the actual battery life is much less. But, if you really want to maximize your battery, dim the screen. Don't use the cd drive, and don't access the hard drive frequently. Disable bluetooth. And, if you aren't using it (which I would be, anyway) disable Airport.