The iSpeaker connects to your audio player via a standard 3.5mm stereo audio plug. The device offers a built-in rechargeable Lithium-ion battery and a built-in digital amplifier. Measuring 10.5 cm x 4.8 cm and weighing 90 grams, the speaker is suitable for iPod, iPhone, or any audio player that has a standard 3.5mm stereo audio plug. The iSpeaker Portable Speaker is priced at $20.99. [GizFever]