Check out Michael Robertson's blog for a review of the Logitech Squeezebox Radio with accessory pack (battery and remote control). Logitech devices all support the MP3tunes music locker so you can listen online without having to run a separate PC. His tests revealed that the device got more than 8 hours of battery life. Adding a battery and remote turns a tethered-at-home stereo component into a take-it-anywhere Wifi boombox.