Need fun, challenging math projects for 7th and 8th graders...?

Question

Does anyone know of any websites (or books I can purchase) that offer ideas for middle school math projects (specifically 7th or 8th grade)? Something that involves a lot of thinking but not expensive or elaborate materials??? I appreciate any help you can give me!

Here's an example: http://www.angelfire.com/ny/brockport/Package.html

Answer 1

Here's a neat site from NASA with some interesting ideas.

http://spaceplace.nasa.gov/en/educators/math.shtml