This past Friday I purchased the 13" aluminum MacBook. I am trying to make the battery last as long as I can without getting a new one. I trained the battery the first night by letting it die and putting it on the charger until I got a full charge. I have one question though. My girlfriend's older PowerBook has battery settings like "optimal battery life" or "better graphics performance". Are these features hidden on my MacBook or are they inaccessible due to the fact that the battery is already 'trained' to know when to use resources, etc. Can anyone help me out?