If you know anything about programming, you will know that true randomness is difficult, to say the least. Randomness in a deterministic environment such as the blockchain, is damn near impossible.
Current random number generators, such as random.org use atmospheric noise from the natural environment (http://en.wikipedia.org/wiki/Atmospheric_noise) created from lightning to generate their random numbers, but the problem is this is a central service, which means you cannot truly be 100% satisfied that the numbers they are generating are truly random. As long as you trust your source, that is fine, but what if you don't?
Enter Randao 1.0.
Now the Randao Contract is released.
On the TEST-NET, the contract address is 0x0a25BCAC5b5A90e3F2dd7Fdf907A6c071b1296Ce, anyone can check it at http://testnet.etherscan.io/.
On production net, the address is 0x6C8060507273A0ff175361C6bf9F86e97f8Cf2C8, anyone can check it at http://etherscan.io/address/0x6C8060507273A0ff175361C6bf9F86e97f8Cf2C8