One of several problems that can plague portable speakers is a lack of stereo separation. The easiest way to remedy this issue is to create a design where each speaker driver is actually housed in a separate unit, so that the left and right channels can be placed some distance from one another. Sony implements this technique in its SRS-M50 Portable Speakers, a compact set that retails for $49.99, and there's no doubt the unit offers better separation than most ultraportable speakers. In fact, overall sound quality is pretty decent, the style is likable, and the design lends itself well to portable use, all of which makes the SRS-M50 a great option for frequent fliers. Read the Sony SRS-M50 review.