In light of the recent discussions here, I thought many would find this 
article interesting:

"How to Attack the Gender Wage Gap? Speak Up"
http://www.nytimes.com/2012/12/16/business/to-solve-the-gender-wage-gap-learn-to-speak-up.html

The gist of the article is in this quote: "But one part of it can be 
traced to a simple fact: many women just don’t negotiate, or are 
penalized if they do."

I have actually been reading Stuart Diamond's book on negotiating, 
titled "Getting More".  In it he points out that there are lots of 
different negotiation styles, and that some are more effective than 
others.  It's pretty eye opening for me, who hasn't had any formal 
training in negotiation.  The biggest a-ha for me was that "everything 
is negotiable", despite the cliche.  Practicing the techniques in every 
situation in life (from getting into an overcrowded restaurant without a 
reservation to asking your boss for a raise) is the way to get better at 
it, and I have to say that I'm starting to ask more and am pleasantly 
surprised by the results.  [Adding to GoodReads now ...]

Cheers,
Shaun