I just bought a iHome 'iHM10 Protable Ipod Stereo Speaker' (for my iPad) at Walmart for $19 (MSRP $24). It requires 4 'AA' batteries (not included) - no idea yet how long the batteries will last. I found the sound, with EXB circuitry for a more increased bass sound, to be quite acceptable. I intend to use this speaker to listen to audio books while on road trips. The speaker does have an ON/OFF switch. Even comes with a cloth carry bag to protect it.