Outdoor bench made from upcycled oil drum (from student competition at London Architecture Festival 2012). I'd love to try this! How about making the slats removable, then it could double as a barbeque grill?
Cable spool bookcase, using wooden dowel rods for separators and attached wheels for moving around - great storage for all my craft books... but I can also see fabric and other fun stuff being stored! [call your local electric or cable company and ask for their empty spools - they come in assorted sizes... that's how I got mine!]