Top Solitario, one of my favorite sites for its quality free paper products, has a selection of 3-D terrain pieces for Dust and other games which can be downloaded, printed and quickly constructed — a bonus is that they also fold flat!
paper model
Paper Science Fiction Ornithopter Model
Toposolitario has a new paper model for you to enjoy: a science fiction ornithopter. The artist points out that a 50% printing, it would work for the now very popular 15mm science fiction figures.
Zeppelin Goldola Interior Model
Rattrap Productions has a free paper model of the interior of a Zeppelin gondola, suitable for 28mm figures.
Steampunk Mecha Paper Models
The Toposolitario site has a nice selection of paper models of mecha suitable for steampunk, pulp or wierd WWII games.