This is a bit out of date, but fascinating none the less.
This seemed like an interesting find: http://in.rediff.com/news/2004/feb/17diamond.htm So who wants to go an expedition and get a few tons of it? 
You beat me to it Kirupa,
I was going to post this on the 15th…
10 Billion Trillion Carat Diamond Discovered
Scientists have discovered a massive diamond with a weight of 10 billion trillion carats - the only problem is, it’s 50 light years from earth,within a burned-out star named BPM 37093.
