More self replicating machines
http://news.bbc.co.uk/1/hi/sci/tech/4538547.stm (probably not really as interesting as http://staff.bath.ac.uk/ensab/replicator/, since it only self assembles from fairly complex preprepared building blocks).
So we're still a long way having to seriously worry, but (link to larger version):

So we're still a long way having to seriously worry, but (link to larger version):