We told you about it a few weeks ago, and now it's here: Amazon is offering free instant streaming of over 5,000 movies and TV shows to its Prime members at no additional cost. Prime memberships, which already include a tempting free two-day shipping bonus, run at $79 for the full year.

No official announcement has been made yet, but Amazon's website is already trumpeting the new deal. Amazon Instant Video, as the service is called, is a major shot at Netflix, the formerly undisputed king of at-home movie streaming. Netflix still has the superior library at over 20,000 movies and TV shows, but that's certainly not set in stone as Amazon's service will continue to grow. 

The news comes the day after Blockbuster put itself up for sale, underscoring the shift from physical media to streaming as the future of movie rentals. That theater will only get more crowded with companies like Apple, Hulu and Google already well positioned to offer competing services. The big fight will be with the movie studios, some of which are already angry with Netflix for what they perceive as devaluing their products.

For today, you can enjoy a brand new way to kill time at home and catch that documentary you keep hearing about. Amazon Prime is free to try for a month.

[Amazon]