OneMonk has posted a free paper model of some standing stones and stone blocks that wold useful as a ruined city.
paper models
Free Dropship Paper Model
Grey Matter Games offers a free paper model of a science fiction dropship, suitable for games from 6mm – 28mm.
Gallic Counter Set For Warmaster
The League of Ordinary Gamer has a set of Gallic counters that you can use in lieu of miniatures of Gauls.
Paper Table Models
The “D4 D6 D8 D10 D12 D20” gaming blog has some free paper models of wood tables for your D&D, fantasy or medieval games.