I never knew about the different types of memory modules available for our iBooks until one of the other posters here mentioned it. I'm referring to the normal memory modules, and the low power memory modules. When I got my Clamshell in August 2001, I ordered a 256Mb module from Crucial.com and that was that. Everything's been fine with it. I was not aware that the more ram you put into your iBook, the more of a drain it is on the battery. I take it that it must be a significant drain for the manufacturers to consider making special 'low power' memory modules. Has anyone here had experience with both types of module? And are the 'low power' one's that much more expensive than the normal DIMMS we use? Its not like I'm going to rush out a purchase a 512Mb low power module at the response to this question, but I did find it interesting when it was mentioned, and maybe it might help others when it comes to purchasing more ram in the future.