The Iron Hand site has a tutorial on building a very nice building-sized laser defense battery for 25mm – 28mm science fiction games, such as Warhammer 40K. These would be great as the focal point of a scenario.
modeling
Making Middle Eastern Buildings
Olicanalad’s Games has an illustrated article on making Arab / Middle Eastern style buildings.
Build An Underground Jedi Hut
Terragenesis has an article on building an underground Jedi headquarters. It would work as a Hobbit house also.
Making A Fuel Depot
Terragenesis has a tutorial on making a nice looking fuel depot from the green floral foam.
I always knew there were wargames applications for that stuff.
Modeling Alien Plants
Terragenesis has a nice article with ideas for modeling alien plants.