Amazon's second generation of Alexa-enabled gadgets is ready to go. The Amazon Tap, a smaller, battery-powered version of the Amazon Echo, as well as the Echo Dot, which can use external speakers for its primary function, should both be heading out to those who purchased them after their recent announcement. The latter is only available to Amazon Prime members who order using Amazon's voice service, with a Kindle Fire tablet or Fire TV. The Tap, along with its cover accessories, are both labelled as "in stock" on Amazon's US storefront.

Both devices represent an expansion of Amazon's Alexa voice command platform, which is itself a competitor to services like Google Now, Apple's Siri, and Microsoft's Cortana. The Tap offers the music playback functions of the original Echo in a small portable package, minus the always-on listening capabilities (instead you have to tap the microphone button). It includes a pair of omni-directional speakers and Bluetooth connectivity, along with a quoted nine-hour battery life, for $129. The Echo Dot is a pint-sized version of the original Echo, with an always-on microphone but without any speakers, which connects to external sound output via Bluetooth or a standard headphone cable. It has more or less all of the available Alexa functions, including info gathering, ordering from Amazon and partner retailers, connected home features, and more.

The Alexa platform is still very much in beta, but Amazon seems to be throwing quite a lot of development and marketing into it, so it's probably not going anywhere soon. The hardware is still a little pricey - savvy buyers might want to wait a few months, since Amazon is fond of exclusive sales on its first-party devices.