My iBook died this morning , so it's time for a new laptop... I'm going to sit on my hands until the announcements Monday, just in case, but when I do get a new MBP, I'm wondering about upgrading the hard drive. The options are 120 GB (from 100) or 7200 RPM (from 5400). A lot of what I do is scientific computing that's i/o intensive (that's the main bottleneck for many of the programs, and it would be nice to run 64 bit versions of the apps, btw), so I'm inclined to get a faster HD. At the same time, the files we work with are around 2 GB each, so I'd like a bigger drive. Are there any other factors that I should be thinking about before I leap? Hard drive lifetime (that's what died on my iBook), heat, noise (not a big deal, but good to know about), or something else that I wouldn't expect? Will I be able to see the HD speed difference, or do they not all take advantage of it for one reason or another (we're having this problem with single threaded programs running on multi-threaded CPUs - no help there!)? Thanks!