It's scientifically impossible to get too much Guardians of the Galaxy, which is a very good thing because it's now available for rent and purchase on on Apple's iTunes Store. For US$19.99, you get the movie in HD, plus extras like deleted scenes, bloopers, and behind-the-scenes details. Bonus: You also get an exclusive look at Marvel's upcoming Avengers: Age of Ultron movie. If you saw GotG in the theater, you know why you need to buy it now. If you missed it, here's your chance to redeem yourself.