The people at Google charged with putting Web multimedia on TV haven't just spent the last few years getting kicked around the living room: The new Chromecast shows the company's learned something from the flops of Google TV and last year's abandoned Nexus Q.
This $35 thumb-sized pod plays audio and video from apps on an Android or iOS phone or tablet, but its utility doesn't depend on the cooperation of potentially uncaring media companies: It can also play what's in any Chrome browser tab.
Setup: Google wins this with a nifty routine that never puts a keyboard on your TV's screen. Instead, a Chromecast boots into a hotspot mode, which Google's Android, OS X, Windows or Chromebook Chromecast app (iOS is due soon) connects to; then you select your network and enter its password on your mobile device or laptop. The only non-obvious part is running the included USB cable from the Chromecast to a TV's USB port or an adapter plugged into an outlet.
Selection: By numbers alone, it's Roku, then Apple, then Google. But Roku's great menu of 800-plus channels exclude the single biggest video site, YouTube. This absence has lasted years without explanation from either Google or Roku (maybe a Google driverless car run over a Roku exec's dog?). This isn't a great fit for playing audio or video stored on a Mac or PC; the Plex channel can handle that but requires a separate server app on your computer.
Apple TV is much better at playing what's on an OS X or Windows computer, and it's the only option for streaming media from the iTunes Store. You also get some obvious streaming sites, like Netflix, Hulu Plus, YouTube, WatchESPN, MLB.TV and HBO Go, but not Amazon Instant Video or Pandora--even as Apple recently found room for the concert archive Qello and the anime site Crunchyroll. AirPlay on iOS can fill in many of those blanks by streaming or mirroring from an iPhone or iPad app (except when blocked by those like Amazon Instant Video or TiVo Stream); OS X AirPlay mirroring isn't subject to that limit but requires a 2011 or newer Mac.
Chromecast users can only send video from Netflix, YouTube and the Play Store at the moment, but that could change quickly, to judge from reports of Chromecast interest from the likes of Vimeo, Redbox and HBO. But the more interesting end of the deal is the ability to mirror tabs from a Windows, OS X or Chromebook Pixel's copy of Chrome by using the Google Cast extension. Encoding and streaming an existing video stream or a saved audio or video file opened in Chrome--call it "AirPlay for the rest of us"--is a kludge that can sacrifice picture quality on a slower computer. But it's worked for me, and it seems a site can't block it unless it wants to exclude all current builds of Chrome.
Interface: Apple and Roku offer spare, simple interfaces with the same defect--each forgot to include a volume control on its remote. Apple has done better than Roku otherwise: on many Roku models, the remote's navigational buttons have the "select" button below them, not in the middle where you'd expect it. Its Channel Store only got a search interface in March. Apple provides an iOS remote-control app; Roku does so for iOS and Android.
With Chromecast, the only interface you see is in the apps you already use; figure out where each puts its Chromecast button, and you're set. And you can control the volume with the buttons on your phone or tablet. (Because the Chromecast streams each program from the Internet after you tap that button in an iOS or Android app, your phone can reboot--as mine did during a test--without interrupting playback.)
Potential: Like any other Apple product, the Apple TV will grow at a rate strictly set by Apple, and so far that's happened at a gentle pace. Buy it with the expectation that its feature set is sealed. Roku constantly adds channels, and some represent major advances. In March, Time Warner Cable subscribers got the option to stream their channel lineup through a Roku. With Chromecast? It's too soon to say. Check back in a month to see how many other Android and iOS apps can stream to this little stick--and what hackers have been able to do with the cut-down Android code inside it. And if it's still on backorder everywhere.