Here's a little bit about a new article in Nature:
The authors looked for regulatory regions of the genome that are conserved across several species (and therefore likely to be functionaly important) but which appear to be missing in all humans. By studying what these regions do in other species they try to figure out if any of these deletions might have been important during human evolution. I won't spoil it encase you haven't read it, I'll just say brain growth and penile vibrissae...
The original paper (it's only a couple of pages):
Another commentary on the paper, with some good critical discussion at the end: