Provide turks with a URL and have them extract FOAF information. This could be part of a service for individuals and businesses that want their information to be accessible to semantic web tools. Once the information was extracted you could easily generate FOAF files to send to users.
Art projects are pretty cool. Like the one project where an artist asked many people to try different types of sheep. The coolest one I've seen is the project called "Ten Thousand Cents" where people were paid to draw a very small section of a 100 dollar bill and then they took all of the animations and stitched them together to have one simultaneous animation of all small sections drawn at once.
I was watching a special on Steve Fossett Missing|Steve Fossett's disappearance and they actually used Amazon's Mechanical Turks to try to find him. I think finding ways that the system could be used to help find missing people on a regular basis (and not just for missing billionaires) would be very interesting. I've included a link that gives a brief description about what they did.
A research paper I am writing at the moment (on plagiarism detection and copyright law) inspired me to answer this question. Mechanical Turk could be used to fight plagiarism. Rather than have teachers attempt to research every sentence that might be copied and pasted, Turks could do it.
Services exist at the moment to fight plagiarism but they may turn out to be more expensive than using Turk and have 2 relevant limitations. First, computers and not humans do the screening and humans are arguably better, and second is that none of the online plagiarism detection tools check printed materials. Turks that are experts in their fields, or even other teachers, might recognize a paragraph from a textbook that they use.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.