A simple iron golem farm that I put together

It's the combination of a bunch of ideas I saw around youtube (Yogscast's house with blocked door, some guy with the lava killing idea) and put into one schematic

The schematic only works on 1.1, because anvil won't work with MCedit, but it's not that hard to reproduce in 12w08a

The world save is for 12w08a, but I put two farms next to each other, so it's kinda buggy, I recommend destroying one

Any ideas on improving the design are appreciated :D

Edit: For some reason, the schematic doesn't work, however I have built the exact same thing in my survival world and it works fine, so I recommend just recreating what the schematic shows

Additional Notes

To use the schematic, put it onto a world in 1.1, then copy it onto the 12w08a snapshot and upconvert it to anvil, or just recreate it