Ask Amazon: Askville versus Mechanical Turk

update (31 dec 2006): I just read about AskCity, a service recently launched by Ask.com. This wouldn't happen to be a coincidence now, would it?

update (30 Dec 2006): My question remained unanswered and was therefore closed...

I just learned about Askville, a new Amazon service described in its FAQ as:

Askville is a place where you can share and discuss knowledge with other people by asking and answering questions on any topic.

On the other hand, I already knew about Amazon's Mechanical Turk, described in its FAQ as:

For businesses and entrepreneurs who want tasks completed, the Amazon Mechanical Turk web service solves the problem of getting work done in a cost-effective manner by people who have the skill to do the work. [..] What if [..] a computer program could ask a human being to perform a task and return the results? [..] The application sends the request, and the service returns the results. Behind the scenes, a network of humans fuels this artificial artificial intelligence by coming to the web site, searching for and completing tasks, and receiving payment for their work.

Two question-based services from Amazon. One aimed at people, one at developers (sorry!), both based on the principle that there's always someone who will answer a question or perform a task, no matter how boring the question is.

Judging on the requests I see at the Mechanical Turk, it takes quite an effort to have a computer program specify the questions; there's a lot of detail in the sample questions I had a look at. The timeline for answering seems long: I saw open requests that had been standing there for weeks.
Asking a questions at Askville seems simple enough: you have 120 characters initially, and 1000 for background information. Answers seem to come in quickly, sometimes within minutes.

The two services do not refer to each other, but they could be complimentary. How does someone choose between the two?

Hey, since I feel like a person, I'll ask Askville in an attempt to get an answer...