The Onion Router is a internet project that aims to anonymize your traffic by routing it through a dark-net with various exit points to the Internet. Normally you would have to install a browser proxy on your machine to access TOR, but now there's a browser available for the iPad and iPhone.
Of course, I had to test it by checking out the Silk Road, a much publicized "Amazon of illegal drugs" that only exists on the TOR network.