Knex roller coasters

http://www.sscoasters.net/

You should check out this website if you like knex and roller coasters as it tells you almost everything you need to make one. I am part of the website (username: untd4eva) and it has helped me create some really cool coasters. To get started you should buy a screaming serpent off ebay( about the only place you can find them) and join this site. This site really has alot to offer