If you’re a PowerMac or Mac Pro user, or use external storage devices with your Mac, you’ve probably got a few spare hard drives kicking around from various upgrades over the years that haven’t even been worth selling off with the plummeting prices of hard drives. Enter Sabrent’s DS-UBLK ($50) and EC-HDD2 ($70). Available on Amazon for roughly half their MSRPs, these external docking stations connect to your Mac using a fast…