As one of its daily deals, Meh.com offers the Acoustic Research Soundflow Soundboard for Smartphones, model no. SP40, for $20 plus $5 for shipping. That's the lowest total price we could find by $27. It can function as a 5,200mAh external battery, and it amplifies music from your smartphone by simply placing your device on top (no Bluetooth or WiFi connection is needed). Deal ends today.