Lifehackers Alternative Guide to Airplay

"AirPlay is Apple's great new media-streaming technology, but unless you've purchased a handful of Apple devices, you're not welcome to the party. Here are the best alternatives to AirPlay that offer even more options for streaming your media."

Airplay is an upgrade for Apple's Airtunes which allows Apple devices such as the iPad or iPod to stream content to an Apple TV box for display on your TV. It has a number of limitations such as which media files it will stream, and also which devices can stream and to where.  What if you don't have an Apple TV box? Not to worry, Lifehacker has an article listing a number of alternative options for you, both hardware and software.