Sodaplay
http://www.sodaplay.com/index.htm
A cool site where you can construct models made of masses, springs and muscles. You can put your finished models in the "sodazoo" along with the other masterpieces, like strange pulsing octopi, spinning robot creatures, dogs wagging their tails, and any other bouncing shapes the computer and imagination can muster.

West Point Bridge Design Contest
http://bridgecontest.usma.edu/download.htm
The competition is now accepting submissions for 2004, so get ready! Here's where the United States Military Academy hosts annual West Point Bridge Design Contest, in which middle school and high school students ages 13 and up compete in teams for a $15,000 scholarship. On the website you’ll find the West Point Bridge Designer software, which provides budding designers with the tools to model, test, and optimize a steel highway bridge.

Kids & Careers, from the American Society of Civil Engineers
http://www.asce.org/kids/
Everything you want to know about civil engineering: what it is, its history, how it touches your daily life, careers in civil engineering, and more. Plus, games and screensavers galore.

Chronic Logic
http://www.chroniclogic.com/
More engineering-related games and software, including Pontifex, in which the player designs and builds bridges, and Triptych, a fast-paced puzzler with rotating, different-colored blocks. You can order the games or try the demos. Visit a related site, http://www.bridgebuilder-game.com/, for additional information about Chronic Logic.