If you want to turn your echo dot into a portable device, you could plug it into one of these:
https://www.amazon.com/YutaoZ-Charging-Battery-Base-Generation/dp/B01LANQT78/ref=sr_1_3?ie=UTF8&qid=1481047139&sr=8-3&keywords=echo%2Bdot%2Bbattery&th=1
I just ordered this to pair with my echo dot:
https://www.amazon.com/DKnight-MagicBox-Bluetooth-Portable-Microphone/dp/B00NXET2MM/ref=sr_1_2?s=aht&ie=UTF8&qid=1480966665&sr=1-2&keywords=dknight
Possibly better than the Anker Sound Core, and close to the $28 Black Friday price.
When I first heard the built in speaker, I thought, "hmm, that sounds better than I thought, about as good as my Oontz". Then I plugged it into my Oontz and it was like, "nope, not even close". But no one in the family is much of an audiophile, and my wife has low tolerance for loud music...
Just got my echo dot last night, and it's an absolute steal at $50 - even better, I got mine for $40.
The most impressive part of the Echo Dot is the microphone system. No need to yell or walk up the device -- you can speak in a normal tone at a normal volume and Alexa will start listening for...