personally I would go with a 5400rpm drive so that the laptop can still get a decent battery life. That is, unless you are using it for video editing or something that demands high HD speeds.
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"Fix it 'til it Breaks."
Jacob - EiC & Director of Technology Mac Pro Quad 2.66 - 4GB RAM 160 GB SATA RAID 1 - 650 GB Storage Quad 19" Widescreen LCDs Accessorized to the Hilt