The problem has prompted a spooky, but elegant, business idea: why not use the Web to create marketplaces of willing human beings who will perform the tasks that computers cannot? Jeff Bezos, the chief executive of Amazon.com, has created Amazon Mechanical Turk, an online service involving human workers, and he has also personally invested in a human-assisted search company called ChaCha. Mr. Bezos describes the phenomenon very prettily, calling it “artificial artificial intelligence.”

Of course the spammers are already doing this to solve captchas :/