In the last five to ten years, the home theater industry got a lot right. High definition video has become readily available, and for the most part, a standard, with most mainstream channels broadcasting in HD. Surround sound has enabled new levels of realism, and the dream of a real movie theater experience at home became well within reach of millions of people. Today, the latest in home theater systems is built upon these advances to merge the home theater into the fabric of family life. The result is a more networked place where families can enjoy all types of media. Here are the four technologies that we think have changed everything.