Amazon explains how to build your own Echo.

The Raspberry Pi is a wonderfully versatile and inexpensive little bit of computing kit, and one that's capable of being transformed into all kinds of gadgets if you know how - and apparently that list of gizmos includes the Amazon Echo .
Alexa Voice Service Evangelist Amit Jotwani has posted a step-by-step guide on GitHub for the benefit of anyone keen to tap into the powers of the voice-controlled digital assistant. Jotwani's job is to help developers get Alexa into third-party products, so he certainly seems well-qualified for the role.
You do need a little coding knowledge and some familiarity with the Raspberry Pi but it's a project that many people will want to tackle - and of course you then get yourself an Amazon Echo clone at the fraction of the price.
Echo friendly
It might be particularly attractive to computer tinkerers outside the United States, as the Echo has yet to go on sale anywhere else up to this point. The downside to the homemade rig is that it's not always listening: you need to press a physical button to get the device to pay attention.