If you put two anvils in a T like pattern, shown in the attachment (Just note, if you see the retextured hotbar, resource pack), and if you try to walk into one if the anvil, with the side of the other anvil, you can walk in it. Also, if you don't think thats enough proof, and think I spawned a anvil above my head, look at this video: http://youtu.be/gVKbPhBf-GI If you are wondering what the black boarders are, I need to fix up Hypercam.
Note, I was in creative for this, but also works for survival.

To recreate:
1. Start any world
2. Spawn two anvils, as shown in 2014-09-21_14.23.18.png, in any way.
3. Walk into one anvil, with another anvil on the side, as shown in 2014-09-21_14.23.43.png
Now you have walked into a anvil.