Google is raising the stakes against Apple by unveiling Nexus Q, a media player that it calls "the first device that lets you create social playlists with your friends." A small, sphere-shaped device, it will work with the newly launched ($199) Nexus 7 tablet and other Android devices to stream media from the cloud, and is designed to be used at home. When you launch the Google Play app, you can make playlists that friends can add to from their own collections. The device can also double as an amplifier, letting users plug in external speakers. It goes on sale for $299 in July.