It's cool. It's cheap. You might want to get one.
Okay, for those of you who haven't heard of them, the Google Chromecast is a little $35 gadget that plugs into the HDMI port on your TV and allows you to watch stream Netflix/YouTube/Google Play videos from your iPad/iPhone/Android/laptop device on your big screen. with more media apps to come. The neat thing is that the Chromecast doesn't stream the video from your device: it connects directly to the source, and your device merely controls it. That means that you can turn off your device or go do something else, and the video will keep playing. There are also extensions to Google's Chrome browswer that allows you to echo your browser tab onto the big screen as well. I tested it with Hulu and Retrovision, and full screening the video worked reasonably well, but not as good as the built in Apps. I also brought up a couple of WebGL demos, and the mirroring worked quite well, but with a bit of lag. Google says support for more services is coming. I'd like to see an extension that allowed you to send any HTML5 video to the screen, but even as it is, it's quite serviceable. It doesn't do as much as the Apple TV, but works with more devices, and is much cheaper.
I'd write more about it, but I thought this review did a pretty good job of going over the details. Thumbs up from me!