When you're a student, your entire life—projects, friends, plans—is on your computer. You need a backup in case something goes wrong, as it almost inevitably will. A portable hard drive like the My Passport Ultra is the security blanket you need.
Its technical benefits start with USB 3.0 compatibility for speed. Included software lets you encrypt the disk's contents and require a password for access, while other software lets you schedule backups, including cloud backups to Dropbox. (Mac users will need to download and install the software after reformatting the drive for Mac OS.) The My Passport Ultra is available in a wide range of capacities, from 500GB up to the recently introduced 4TB.
It's also a fashion statement, with multiple colors available: white, black, blue and berry. There's also a pink model sold only at the WD Store; a portion of the proceeds go to The Breast Cancer Charities of America. You can also get supplementary "grip packs" ($13 each) in complementary colors that include a protective bumper that goes around the outside of your drive, plus a matching cable.
Retail prices range from $50 for 500GB to $140 for 4TB (Amazon price), but note that the 4TB model (currently available in black only) is out of stock at many retailers we checked, including Amazon.