It's interesting to see how Amazon is opening up their infrastructure as web services. I just heard about Amazon Mechanical Turk, which is subtitled "Artificial Artificial Intelligence". It's a clever idea: if you want a computer to do a task automatically, but the job is too hard for a computer, then farm it out to humans. Kind of like SETI@home in reverse. Where SETI@home farms out difficult computations to lots of computers (which are good at computation), Mechanical Turk farms out difficult image recognition to lots of humans (which are good at image recognition).
I'd heard of this approach before, for example, a security firm handing out images from security cameras, asking people to tell whether there's a person lurking in the photo someplace. Amazon seems to have set this up to find businesses in photos for their BlockView maps.
Then once they had it set up, they exposed it via a Mechanical Turk web service. It's a great idea. Since they had the infrastructure built, building a web service opened up their marketplace of human workers to others who wanted to provide work and needed to find people. That will bring more human workers (since there is more work there of a more varied nature), which will bring competition among work providers to pay well, which will bring more workers. Capitalism in action. It'll be interesting to see if there are enough businesses with work needing to be done to give it critical mass.