I recently read “the Genius in All of Us” by David Shenk. An interesting and thought provoking book, which challenges commonly accepted ideas about how genetics works.
In it, he mentioned two particularly interesting bits of research.
The first involved mice, and diet. The original paper on this research can be found at http://chd.ucsd.edu/seminar/documents/Morgan.08.pdf. It reads like a Scientific Journal paper (most likely because it is a Scientific Journal paper), but the interesting bit is that the authors observed that by feeding a yellow mouse a specific diet, her offspring would have brown fur. And more interesting still, this genetic alteration would continue through future generations.
The second bit, from Washington State University was similar, and involved exposing rats to a couple agricultural chemicals (pesticide and fungicide). The result of this was a reduced fertility in the rats, and the next four generations of offspring (http://www.americanhealthcarefoundation.org/fibromyalgia-md/ArticleE.cfm is a nice, relatively non-boring summary).
There appears to be some debate about how significant a role epigenetic inheritance plays. It nonetheless causes one - upon hearing news that scientist have discovered the “anger gene” or the “alcoholism gene” or the “gay gene” or the "sociopath gene" or… - to ask oneself “Did the gene trigger the behavior, or did the behavior trigger the gene?”