Kinivo ZX100 3.5mm Mini Speaker $15 at Newegg

Newegg has the Kinivo ZX100 3.5mm Mini Speaker with Rechargeable Battery for $20 - $5 off with coupon code EMCJHHB223 [Exp 1/1/13] = $15 with free shipping. Currently offered around $20 and up online. Features Expansive Resonator Construction Design to give the best low frequency output, and 360° sound with rich bass resonance.