Steven Pinker, just out with a new book (The Better Angels of Our Nature: Why Violence Has Declined), gives a talk outlining how rates of violence are falling in the world, and the causes of this. Excellent, highly recommended, and available for free in high resolution:

Progress is actually progress. Hans Rosling would agree.

Update March 30, 2012: I really should clean up my notes and add to this post, but this review by Peter Singer sums it all up nicely, so I won’t bother. But it is worth a read, 800 pages and all.