>> b) Is the "Low Power" RAM really worth that much more? Does it help >> battery life that much? Any experiences with it? I got the 512 low energy stick. I personally see a difference of about 10 or so minutes in battery life. Also, the powerbook runs a lot cooler (the keyboard/hand-rests anyway) then when there was a "normal" 256. Q:What is with this low profile memory stuff? A: The low profile is necessiary for the new ibook models - icebook,ibook2,ibook500 and above. This is because the keyboard in the ibook is lower then the one in the clam shell. So if you put in a "high" profile memory, it could force the keyboard to push up and possible cause damage to the memory/system. The clamshells do not need the low profile memory however (from what I have heard). When the first 512's came out, people complained they couldn't use them in their new ibooks because they were too big. That has sense been fixed with the new "low profile" one's. thanks, Ian Sidle