The MTX Audio iThunder is the latest in a flood of portable iPod speakers, and it sports more of a traditional boom-box look than some of its competitors, such as the Altec Lansing inMotion IM7. It works with and charges any Apple iPod model with a dock connector and can be used with other players via an analog line-input jack. The iThunder deserves its name, as it's got some serious rumble to it, but on the flip side, the speaker often sounds as if it's about to shake itself apart. That said, at normal volumes sound is surprisingly good, though the system does have several sonic flaws and certainly doesn't hold a candle to larger, more-expensive portables such as the Apple iPod Hi-Fi. Still, if you're looking for sheer volume and beefy bass in a very portable package, this is the one to get.