totalbc - Total Bitcoins in circulation (delayed by up to 1 hour])
It seems like it actually gives the value in satoshis for some reason, but that's not the really confusing part.
What I wonder is if this value really represents the "total Bitcoins in circulation", or just "total Bitcoins mined". Does it account for the "lost" Bitcoins which will never again be possible for anyone to use because the private keys are no longer accessible by any human or machine?
If not, is there a source which lets me grab that number? It's pretty useless to know how many Bitcoins have been mined; I want to know how many currently "really exist", as in, are actually in circulation, or can be "circulated".