Over at Discovering Biology in a Digital World, Sandra Porter asks_ Why is sequencing a human genome so expensive?. I chimed in in the comments talking about why Jim Watson's genome was so much less expensive than the other current genome assemblies.
The other two, of course, are the Human Genome Project's reference sequence, and J. Craig Venter's genome, which was released just the other day. Did I mention that it was released in PLoS One, so it's open access? Yay!