Nuclear mining operation either in a power plant or in a submarine. It will already have a water cooling system set up for the fuel rods which can be used for the mining rigs as well. Any excess electricity generated can also be sold for more profit.

3. Large Affiliate Market/Network

Just like the Bitcoin Ad network above we need a large affiliate Ad network like the likes of Commision junction, Maxbounty, Clickbank, etc. The network would be 100% Bitcoin based. The advertisers would pay in Bitccoin and publishers and affiliates would get paid in Bitcoins. The ad network should be a general purpose network offering  a wide range of products and services for promotion.