Google today launched notable new challengers to the Apple TV and iPad families, starting with Chromecast ($35), a plug-in dongle for accessing online videos and music on an HDTV. Chromecast is compatible with iOS devices — it uses the device as the remote, and to stream content to the TV. Users plug Chromecast into an HDTV, connect it to Wi-Fi, and the device controls streaming of content from the Internet, offering some of the functionality of…
