If you're looking to turn your Raspberry Pi 3 into a usable PC, you'll probably want an external hard drive to provide additional storage. Western Digital's newest PiDrive might be the answer.
The Raspberry Pi 3 is the first version of the board that has the processing power to be a full-fledged PC. It has no internal storage, so you need an SD card or external hard drives to store files.
Not all external drives work with Raspberry Pi boards, but the PiDrives are compatible. Western Digital says it tweaked the drive's magnetic recording and electrical set-points to reduce the power draw compared to a standard hard drive.
The new PiDrive drive has a USB 3.0 interface, which can connect to the Raspberry Pi's USB 2.0 port.
A BerryBoot installer, available for download from Western Digital's website, can load multiple programs or operating systems onto the drive at boot.