And I completely forgot the link, sorry. http://www.newscientist.com/article/dn12429-three-ways-to-le...

I read so much stuff I got my sites mixed up. It wasn't here on HN. There were 2 stories I read in the last week that kind of tied together. The first one(can't remember where) was describing a hypothetical way to use the Casimir effect to propel something through space. There was a more detailed story in New Scientist that talks about using metamaterials and the Casimir effect to induce levitation at extremely small scales. The link I made in my mind was between those two stories and a third, which was about artificial gecko feet. The gecko has an extremely powerful grip because its feet have tiny hairs that extend down to the level where they are able to interact with the van der waals force of molecules on something they are touching. I think the stray thought I had was a) we can build metamaterials(think invisibility), b) we can build artifical materials that mimic and work like gecko's feet, c) if you can actually induce the casimir effect and generate propulsion-ish forces then: Make millions of the little microscopic propulsion thingies, attached to structures like the gecko's, scale that up so you have trillions of little propulsors, and you might have some new fangled kind of engine. I'm a web designer, not a physicist. But it sounds cool. =)