I've been on the fence about getting an external hard drive to back up my system via Time Machine and am thinking about finally biting the bullet and getting one. Here are the specs I'm looking for: At least 500GB of space (my iMac's internal HDD is 250GB) Firewire 400 or 800 A manufacturer's warranty of more than 1 year I've been looking for some time but it seems most external hard drives have gone the way of USB 2.0 (of which I'm using all the USB 2.0 ports on my iMac and don't want to have to bother with a USB hub). The only one that I have really found to fit my situation is the Seagate FreeAgent Desk for Mac 500GB USB 2.0/Firewire 800. However, that is priced pretty high - I'm looking to spend no more than $100. I am open to purchasing an internal HDD then putting it in an enclosure but have no knowledge of what I would need to look for.