When you think of a portable storage device, you think of something that can be plugged into a computer's port to provide extra storage space. Well, that's true for the most part, but some can offer more, such as really fast speeds, a lot of storage, a convenient backup solution, or a built-in mobile media server that works even when not plugged in. Here are our current favorites that collectively offer all of the above, and then some. ©2014 CBS Interactive Inc., a CBS Company. All rights reserved. Used by permission.