Sports Memorabilia is huge industry. Memorabilia allows devoted fans a tangible tie to emotional moments in sports history. And this week, we're featuring some really special pieces: A signed helmet by Warren Moon, the only player to be in both the Canadian Football and NFL Hall of Fame. And a signed Birdhouse skateboard by arguably the greatest ever in his sport, Tony Hawk. Sorry... There was a John Elway-signed helmet, but it sold the moment it was put online.