To follow up on my post on human computation, I should mention Amazons new Mechanical Turk. It's a sort of a broker of human computation tasks (HIT's, in their terminology).
The basic idea is that requesters define a HIT and people get paid to perform these task.
I wondering what the prices of HIT's will be. The minimum commission charge is $0.005 per HIT, which isn't a lot. However, solving these tasks might appeal to people in countries where the average salary is very low.
It's an interesting idea. I'm sure we will see some exciting applications of it.