[mobileman]

Angular resolution of a lens is a function of lens diameter, and cell phone cameras have very small lenses. For small lenses, anything above 2-3 MP is just using a bigger file to record the same blurry image from the lens.

But wait, it gets worse. A small lens also doesn't gather much light, and if you increase MP, you're spreading the same number of photons over more sensor elements. That means you need to amplify each pixel's signal more, so you get more of that crappy shot noise you tend to see in pictures taken on a phone in less-than-ideal light.

Bottom line: Unless you've got the lens diameter to use it, increasing MP past a certain point is a disadvantage. (Although it sells phones to people who think "more is always better").

My brother has a cheap tmobile phone that takes 5 mp pictures. The quality is very good. This phone was $29 with new contract.

[dwhitman]

My brother has a cheap tmobile phone that takes 5 mp pictures. The quality is very good. This phone was $29 with new contract.

I'm sure the quality is fine; people obviously derive a lot of value/pleasure out of having a convenient camera on their phone. If the pictures were unacceptable that wouldn't be the case.

I'm also sure that unless the lens on his phone is much bigger than what's on any phone I've seen, the picture would look every bit as good at 3 MP. Except it'd take up less space. And the camera (everything else being equal) would do better under low light conditions.