Amazon is running a promotional offer, sending you a free copy of Gravity rush as well as a protective film if you buy a PS Vita:
For a limited time, get “Gravity Rush” and PlayStation Vita Protective Film with the purchase of a qualifying PlayStation Vita console.
This works with both the Wifi and the 3G model, but the offer is, of course, limited in time. Gravity Rush is one of the most popular games on the PS Vita today, so hurry up while the offer lasts. There are other Vita bundles like this available, but they are pre-orders.