Design competitions are a great way to exercise and show off your modeling skills. Every so often Google hosts a competition with cash prizes, such as the recent shelter design contest, or last year's bridge modeling contest, which I helped judge.
But if you're in it for the bragging rights and not the money, check out the SketchUp 3D Challenge Site. Every 2-3 weeks someone posts an idea for a competition, and readers can vote for the winners.
The latest competition is for the design of a sports stadium. Hurry up - entries can be submitted until Nov 11!
Teachers: keep an eye on the 3D Challenge site and if a topic comes up that would interest your students, have them enter. Extra credit for contest winners!
Anyone can design anything in 3D! www.3dvinci.net