If you have a roof rack, here is a cool idea for building your own brackets to hold stuff on it. If you buy these things yourself it gets pretty pricey (well over $100). When I first saw this write-up I thought the stuff was plastic. Turns out its wood.
http://www.instructables.com/id/How-to-Make-a-Thule-Portage-Canoe-Carrier-for-Abou/