Ok, so my stock HD is over half full, but it is slowing up! My iTunes library (85GB) is on there, so I am sure that doesn't help speed things up. I have read great things about the WD scorpio drives on NewEgg. People say it is almost as fast as the 7200RPM 500GB version, some say it is slow. Obviously it won't get 100% good reviews, as nothing does. So bottom line, What is a safe bet to go with? Id be willing to spend $20-$30 more to get more storage.. ie; 500Gb 5400 rpm WD is $89, the 500GB 7200RPM drive is $100ish, and the 640GB WD is $119. I only want to buy one HD, so future proofing is important. I have one 500GB LaCie External now, and will probably just use my 250Gb as an external as well for now.. I always have trouble making a decision about these things..