Since there have been some questions up here recently that bring up the edge cases in which people can gain reputation without actually contributing much, I will add one more way that has recently been getting worse and worse (at least in my experience).
Someone posts a question. It is relatively simple and answer involves a link to a particular page of the documentation with perhaps a quick code sample on how to use it. You do this, get a few upvotes, all is well. Then, maybe fifteen minutes later, another user comes along and answers the exact same thing you said. This user will probably not get the accepted answer, but since the answer is in fact correct they will get a few upvotes. Theoretically, I could simply go around to C# questions (which I know nothing about), see what answer gets upvoted and quickly post something that is pretty much the same thing.
Is there anything to be done about this? Is it even a problem? I believe that it just adds noise to the site to have several answers that all say the same thing, not to mention the gaming aspect of it that people can gain reputation by not knowing anything. I have noticed a few users actually post comments on these kind of answers along the lines of "This was already said by so-and-so, you should remove this answer to reduce the noise" — is this the right approach?