Portable Sound Laboratories iMainGo XP

Small, lightweight, combines speakers with protection, surprisingly good sound, two headphone jacks, and audio-in, rechargeable battery

Battery problems, two power switches, no external volume control, sound distortion at high volume, iPhone 3GS and iPhone 4 smartphones don't fit perfectly

While the weight and size might be somewhat tolerable if the sonic performance was excellent, it’s not. The four small drivers inside iMainGo XP are only decent at average listening levels, without the sort of distributed size and frequency response...