[quote name='basilofbkrst']I think it's somewhere around 640. I recall reading somewhere here that more space than that equaled a bigger physical drive that did not fit.[/QUOTE]
What, what, what? Simply not true, you just need a 2.5" HD with a SATA connection....aka a laptop hard drive. Any 2.5" SATA hard drive should work, some better than others. The largest one out at the moment is 1TB. I believe the biggest 2.5" HD at the moment are 1TB, 750GB, 640GB, and 500GB. I have a 500GB in my slim and a 320GB in my fatboy.