The Amazon Prime Air is NOT available yet. It is NOT a joke that they are going to use Drones for delivery within 30 minutes. According to Amazon, it is targeting 2015 to start this service if given the blessing from FAA rules and regulations.
Here is a video by Amazon on their test flight.
According to TechCrunch, the drones or Octocopters can carry up to 5 pounds and deliver within a distance of 10 miles. If you want to know more, click on the below link.