Sengoku Jidai is a set of quick play samurai skirmish rules. There’s also a Korean supplement.
World War II Skirmish Rules
The Tyneside Gamers offer a set of World War II skirmish rules. Lots of other rules sets at the page also.
Aerosan Paper Model
Mayhem In Paper offers a free paper model of US and Soviet aerosans — propeller driven sleds.
Four Musketeers Skirmish Rules
Black Hat Miniatures offer Four Musketeers, a set of skirmish rules / scenario in which the Musketeers must retrieve the Queen’s earrings.