I like sleeping with this Mumal from Semk. It may look like a typical stuffed toy but it’s a perfectly serviceable speaker. I connect this to my iPod and hug it close at night and I can sleep with some tunes on without disturbing my sleepmate. No additional power needed for this.
They’ve included an amplifier powered by double-A batteries but I’m happy enough with the cute golden alien bunny speakers so I haven’t had a chance to try it.