Mega Pixels - how many do you need

01.23.12: This questions comes up a lot and I have done some research.


The simple answer is 12MP.


The real answer is it depends ... and that is why there is no definitive answer.


To answer the question for you, you need to ask yourself questions:


1. Are you shooting in low light? Larger sensor and more mega pixels. 
2. are you zooming and then cropping? More mega pixels.
3. are you printing large pictures? More mega pixels.
4. are you mainly viewing on a computer? Less mega pixels.
5. how large an image sensor? The larger the better.


Resources:
A technical resource to help explain.
A print resolution chart that might help.
How Many Pixels Do You Need?
The best DSLR answer.