I found an interesting Japanese (I think?) site with some free papercraft dioramas depicting various games. I've found a Minecraft one as well as a Portal-themed piece. The Portal one is especially clever; I'll have to build it! You will have to sift through all the weird art, but the papercraft ones are easy to spot amongst all the weirdness.
http://tubbypaws.blogspot.com/search?updated-max=2011-04-25T13:55:00+01:00
http://tubbypaws.blogspot.com/search?updated-max=2011-04-25T13:55:00+01:00