Amazon's Alexa Voice Service can be implemented on a Raspberry Pi and now, with support for "wake word" engines, you can build your own Echo-alike system ... a PiCho? A PEcho?
http://www.networkworld.com/article/3138984/hardware/putting-alexa-on-a-raspberry-pi.html
https://github.com/alexa/alexa-avs-sample-app/tree/79b7df7aaa4c5304446f59c0bd3ee2589b245115