When you quote someone their nick wil be in header of the quote, with a small link you can click if you want to read the original post.
Since there is space on this header line, I suggest also the time/date of the post to be shown. This might be interesting in some cases, maybe especially when multiquoting so you can see the time span of the process.
example;
http://www.flyertalk.com/forum/14076802-post2286.html