Here is a blog entry from a very big Tolkien fan (evidently, a movie fan). His (and co-conspirators') effort seems to have been about a week, and the results are, um, sweet!

Minas Tirith

The Battle of Pelennor Fields

The question I have is, did they eat it or save it? (What would it go for on eBay a few years from now? What would shipping be?)