Speaker Cone Materials

I recently bought new studio monitors for my rig. Made by KRK, the V6 features a cone made from kevlar. While it doesn't render the speakers bulletproof, the yellow sure looks nice (and the speakers sound great!) This reminded me of something I'd heard a long time ago about speakers cones made from banana fiber! A quick search on the web found this Treehugger article about cones made from bamboo, and in the comments is a link to the Fostex banana cone speakers. They're not yellow, but it's a cool idea! This page has some info on other materials used for cones, such as carbon fibre, paper, plastics and more!