Remember those scenes in The Matrix where the heroes could learn anything in a few seconds by having it directly injected into their head? That was awesome.
To actually do that, we would have to understand completely how the human brain stores procedural memories, and modify that to obey the new set of skills. Perhaps we would do this by "patching," having someone have a complete brain scan, learning the skill, and then having a brain scan again. Noting how the neurons changed their configuration may explain how the brain "learned" that skill. Especially if we observe a particular pattern in doing that, and we try applying that pattern to someone who has not learned that skill. If that makes them learn the skill, then we have it.
This would drastically speed up education and training. Everyone could have a PhD level education in multiple fields, and very very exciting things would happen. Also, with such a high level of expertise going around, people would tend to be wealthy. If you want a new job, retraining yourself for an insanely high paying position takes minutes.
Now, this is very unlikely to happen with our knowledge the way it is. We know next to nothing about how the brain works. Almost any experiment we could do to find out more would be infinitely creepy and unacceptable. (Mess around with people's brains?!) Also, any change we do is more likely to make a person brain-damaged instead of smarter. Neurosurgeons in fact consider any modification they make to be brain damage of some kind, since it's as difficult to do as fixing a butterfly's wings with a hammer. While blindfolded. We only get one brain each, and not wanting it destroyed for the sake of science (or anything else) is reasonable and sane.