SuppliesK'nex for some of the amusement park & physics applications: http://www.knex.com/Shop/site_search_portal.php?func=1&words=engineering+kitsLEGO Mindstorms if you want to get into robotics: http://mindstorms.lego.com/en-us/Default.aspx there are even FIRSTLEGO League contests thereZOME construction kits: http://www.learningforallages.com/zome.htm good for 3D designsVernier or CBL for data collection- temp sensors, motion sensors, etc: www.vernier.compulleys, levers, etc..motorspropellorsrubberbandspopsicle stickswheels & axels- or even old CD's, plates, cups mousetrapslots of card stock, cardboardsolar cellsballoonstoothpicksstrawsweightsbalsa woodpipe insulationmarbles & balls of different sizes and weightstoy carstissue paperstring, yarnfoameasy cutters for woodpinswood glueand obviously rulers, protractors, compasses, pencils, scissors