Mechanical Turk has a terrible person hours:revenue ratio if you live in a developed country. Not as familiar with the others, but I think Elance tends to pay pretty poorly too.
For example, a "which of these things is not like the other ones" type task might be estimated as taking 15 seconds, but if you're in the zone you can do them in 5 seconds, netting you 3x the hourly rate.
But thanks anyway.
Recovery from child sexual abuse. I talk about that sort of/some on a blog called November West.
Raising and effectively educating very challenging children. I talk about that on a site called Kids Like Mine.
Getting well when doctors say it cannot be done. I talk about that on a site called Health Gazelle.
I don't know how to get traffic or effectively monetize any of them, in spite of the big reaction it often gets out of the handful of people that read them.