The 5D1 surround sound headphones

You can't get true surround sound out of just two speakers (well, at least not very easily). There's only one option — adding more speakers — which isn't such a big deal for home theater systems,
but with headphones it's a little more complicated. The 5D1 gets the full surround sound effect by adding some extra speakers that pop up like a pair of wings. Oddly enough these aren't the first pair of surround sound headphones with extra speakers we've ever seen, but it's the first pair to come complete with its own 5.1 channel USB soundcard so you can just plug it into your PC and use it without having to shell out for a new card.

[Via The Red Ferret Journal]