Hmm I searched technopunk and could only come up with the music genre. Didn't see much in the way of books. Cyberpunk, I've heard of--I think that's when you've got a really technologically advanced society that's falling apart somehow (so, potentially a dystopia too), and protagonists that are at the bottom of the social structure. Eoin Colfer's The Supernaturalists comes to mind for me. And maybe The Running Man? Wikipedia also cites The Matrix. So it's not different from sci-fi, it's just a specific subgenre of it.
Then again, maybe you had something entirely different in mind.