Wyloch has some good tips here for modeling ruined corners. Corners are among the strongest parts of a building, so they will naturally be prominent parts of ruins.
The Miniature Wargaming Editor
Near Run Thing Napoleonics Rules
A Near Run Thing is a set of Napoleonics rules by Peter Hunt of the Hong Kong Society of Wargamers. From the members list, it seems that Hong Kong has quite a thriving miniature wargames community.
Back to the rules: A Near Run Thing apparently once was available as a commercial set, but now is revised and available on the net. Peter Hunt writes:
1572: The Lost Expedition
1572: The Lost Expedition is a roll and write game designed as a one page, ultraportable game. In it, you are a conquistador trying to reach the Atlantic after a failed expedition.
Modern and Sci Fi 6mm Buildings
Germ’s World has a large collection of paper models for wargames in 6mm scale. These would be useful for, say a BattleTech game, or maybe Epic 40k. There are hangars, moon bases, factories, space docks and middle east buildings.