Heyas...
Using a Canon 10d with 6.3 effective megapixels on a CMOS sensor. I think perhaps there's an important note here that MegaPixels really only determines the size and resolution of the image, not necessarily the 'quality.' For example, a 4 Megapixel camera could take a standard 4x6 photo better than my 6.3 provided it's got better sensors and optics. This is my understanding of digital technology. So if you want big pics than you need big MegaPixels... but to my knowledge, again, this is the only reason for having more megapixels.