The unbreakable metal that (sometimes) comprises Wolverines skeleton and retractable claws, Adamantium would actually be very useful in the real world. If it is light enough to be grafted onto a Human skeleton, but still unbreakable, the potential uses for the metal would be incalculable. All vehicles could be made essentially crash proof, for a start. Next, we come to bridges and skyscrapers and from there we go to all sorts of other possibilities, such as military applications. Yes, there is a lot to be said for an unbreakable metal that is lightweight. The only question is; how the hell would you cut it in order to fashion what you needed from it?