Google Knol Archive

Earlier today Google announced that Google Knol is now open to the public. Danny Sullivan has an awesome overview of how Google Knol works.

I thought this would be a good time to compare three crowdsourced encyclopedias: Mahalo, Google Knol and Wikipedia. Each one takes a different angle on why you should contribute.

Do you participate in any of these crowdsourced encyclopedias? If so, what factors helped make your decision? Was it to help the "greater good" or was it a financial decision?

Here are some thoughts on each encyclopedia and why people contribute to each: