Is there any possibility of actually harnessing energy for our purposes from dark matter/dark energy? This probably isn't a very well worded question, but it seems to be reasonable that if there is so much of it all around us and influencing all the normal particles/matter/whatever it could be tapped into...?
I understand what you mean and I don't think it is possible with our current understanding of physics.
We have no idea what it is so there really isn't any way we can harness it and I could be wrong, but I don't think advances in the future will let us harness it either.
I think the next thing we try to harness is the energy from the Sun. Pretty obvious, but if we could develop some large scale method of energy collection, it would solve the world's issues with energy x1000. Not talking solar panels here, or at least earth based ones, those are bush league and largely inefficient.