The nice touch is that the information is presented so that students need to check their critical thinking to see why there's a problem with this bird-lover's exhibits. A great challenge for thinking skills or a discussion of scientific research. Here's an entire site devoted to chess, from entry level to serious competitor. There's a whole range of tutorials and simulations, as well as links to some commercial products and services. Worth a look if you have students who are into chess, or if you're after a strategy game site.
Students work in teams to create and manage a fictitious portfolio over several months.
The contest has extensive teacher help, excellent documentation, and serious prizes. Worth a look for middle or high school business, economics, or special interest programs. This is a nice collection of interactive math activities that require some real thought. These puzzles are surprisingly kid-friendly, though some of the screen interface is a little rough. Well worth a visit.