I say a "somewhat" portable iPhone and iPod speaker dock, because though the Bose SoundLink Air can be powered by a battery, the SoundLink Air doesn't include one - Bose's rechargeable lithium-ion battery is an additional pay-for option. My review unit didn't include the battery, so I couldn't test the SoundLink's portable features. See all speaker reviews.
The all-black SoundLink Air measures 307x103x171mm; it weighs 2.1kg. I rarely comment on power bricks in my speaker reviews, but the SoundLink Air's is worth mention (sadly, not to praise it): Though I appreciate the integrated cable-storage groove, the wall-wart style power brick is massive. That width is the biggest problem, since it blocked at least two - and often three - outlets on the power strips I tried it with; it also blocks both outlets in a standard two-outlet wall plate.
On the front of the SoundLink Air, near the top, sits its single LED, which indicates whether the speaker is successfully connected to a Wi-Fi network. When I first started testing the system, I thought there were no buttons save for the Reset button on the base of the unit. In fact, though, a pair of nearly invisible volume buttons sit on the right-hand side of the unit. You use either your AirPlay audio source or the included thin, plastic remote (4.3 inches tall and 1.5 inches wide) to control playback. The remote includes power, mute, volume, auxiliary-input, play/pause, previous, and next buttons.
If you're paying close attention, you'll note that this means that there is no power button on the speaker itself. Unless you want to unplug and later plug in the Sound Link Air to turn it off and on, you'll need to use the power button on the remote.
On the back of the unit, you'll find a connector for the power brick, a 1/8-inch (3.5mm) auxiliary-input jack, and a Micro-USB port. That last one is used only during the setup process: You visit bose.com/wifisetup on your computer to download an app (available for Mac and Windows) for configuring the speaker system; during this process, you connect the SoundLink Air to your computer using the included Micro-USB cable. Alternatively, you can hold down the Reset button on the SoundLink Air, which creates an ad-hoc wireless network; you then connect your computer to that Wi-Fi network and direct your browser to the SoundLink Air's special IP address for setting up the unit.
Once the SoundLink Air is successfully on your wireless network, you can send music (or other audio) to it from any compatible AirPlay device, such as any iOS device or iTunes on your computer. When you do, you'll be treated to satisfying, room-filling sound. The speaker can get very loud, though I did notice occasional discrepancies with volume-level behavior: When I used the speaker's remote to adjust volume, the iTunes 11 volume slider didn't consistently move along with it, the way it normally does when controlling an AirPlay speaker. However, the volume slider on my iOS devices did move in tandem when streaming to the SoundLink Air from my iPhone or iPod. This may well be an iTunes 11 issue, and it's a minor one at that.
The SoundLink seems tuned to boost bass levels relative to other frequencies; if you like a little extra kick, you'll like the effect. The overall sound is otherwise crisp and clean. I did notice a bit of low-end distortion at peak volumes when playing bass-heavy music, but dialing down the volume a smidgen alleviated that distortion quickly.