I once heard somebody say that to overcome the absolute supply limit of 21 million bitcoins, one could start their own block chain.
Besides the adoption concerns (most likely nobody would accept the new block chain as genuine in the currently existing Bitcoin network even if it had its own genesis block and wasn't just a fork), are there any networking problems with this? If, hypothetically, the adoption concerns could all be overridden, would there be any data conflicts with the existing block chain? Is the Bitcoin protocol designed to be able to use more than one block chain? Can the client handle it?