We've reviewed a number of portable speakers for the iPod, but none are as ultra-portable as the MacAlly PodWave, which provides stereo (left/right) speakers at the ends of a tube 3.3 inches long (just wider than a standard iPod) and just over 1 inch in diameter; it weighs less than an ounce. When in use, the PodWave sits on top of your iPod, connected to the headphone jack -- it fits standard iPods much better than iPod minis and shuffles due to the mini's off-center headphone jack (and the shuffle's smaller-than-the-PodWave size), but functions just as well with all models -- and puts out surprisingly good sound. That's not to say the sound is going to compete with that of full-size speakers; the PodWave's output is significantly lacking on the low-end and a bit tinny, not to mention that output is seriously limited by both the PodWave's size and its power source (a single AA battery). But the PodWave's output is nowhere near as bad as we anticipated given such tiny speakers; it's much better than the transistor radios we listened to as kids and certainly adequate for those times when you want to listen without headphones but don't have room in your bag for some of the better (and more expensive) systems we've recommended. We were also impressed by the lack of distortion: With fresh batteries and the iPod EQ disabled, we were able to play music at nearly full volume without crackling or buzzing. (Enabling certain EQ settings resulted in more distortion at high volume levels, but we've found that to be the case with a number of speakers and headphones when used with the iPod's EQ.)
The PodWave includes a dedicated on/off switch to help extend battery life -- the unit should provide about 8 hours of playback per battery, depending on your listening volume. (Since the PodWave uses the iPod's headphone jack, volume is controlled by the iPod.) As a bonus, because the PodWave is so portable, it turns the iPod into a great travel alarm clock -- you simply set your iPod alarm to play back music, turn up the volume, and make sure the PodWave is turned on.
Our only minor annoyance with the PodWave was its tendency to rotate freely -- unlike some other iPod accessories, the PodWave doesn't include a "nub" that fits in the iPod's remote jack to prevent the unit from spinning. On the other hand, this makes it easy to access the iPod's hold switch -- you can simply swing the speaker unit out of the way. It also means the PodWave can be used with Apple's iPod shuffle, although the PodWave is significantly larger that the svelte shuffle.
If you want to be able to listen to your iPod on the go and don't care about ultimate sound quality or loud volume levels, the PodWave is a nifty accessory that provides far more utility than you'd expect given the measly amount of space it takes up in your bag.
[Note that although the PodWave is clearly targeted towards iPod users, it should work with any portable music player.]
Update 2/24/05: MacAlly has released a newer version of the PodWave that's slightly bigger than the original; we've updated the above review to reflect this new model, as it completely replaces the original, which was only available for a short time. The new model is slightly bigger (approximately 1/8" longer and just under 1/4" thicker in diameter). It also has a shallow "notch" on the bottom that matches the location of the hold switch on 4G and photo iPods; this reduces the amount the PodWave rotates when in use, but doesn't prevent it completely. Most importantly, the new model offers improved performance -- the sound is much less tinny.--Dan Frakes