Many companies, like Incase, use neoprene or wetsuit material to make their laptop cases. If you can get your hands on a second-hand wetsuit, you could make your very own laptop case.
Tinkerlog has simple and easy instructions with photos that any novice could follow. The hard part will be getting your hands on the neoprene, but maybe you could get lucky at a local thrift store or Goodwill.
Has anyone made their own laptop sleeve?