Ghost-white, feather-light, and eminently portable, the Altec Lansing inMotion lets an Apple iPod fill a small room with gorgeously transparent sound. The only thing you lose is bass, which is understandable in a system so small (8 inches wide by 5.4 inches deep) and light (15 ounces).

The inMotion had the best frequency response of any of the speakers we tested, with an even sound from 90 Hz all the way up to 20 kHz. That translates to perfectly precise sound; in a song by Garbage (a band known for dense production) we could pick out several separate tracks. Acoustic guitar sounded delicious, with the sound of fingers and picks coming through clearly. Bass was slight: We'd call the sound bright, not harsh, but these speakers aren't for hip-hop.

The inMotion runs for more than 20 hours on four double-A batteries, or it can power and charge your iPod with its AC adapter. If you want your iPod to sing you to sleep in a hotel room or keep you chugging along at work, you couldn't do better than this.