I'm afraid that the photos from camera phones always look awful on the computer screen. They are best kept for MMS messaging in my experience, when they are viewed small on a low-resolution screen.
You can try tools like noise ninja or neat image (try googling) to try to reduce the noise, but basically, the sensor is too small to be able to produce decent quality images, especially in poor light. The dynamic range (range of brightness levels that can be recorded in one picture) is also very poor on camera phones. This means that no detail shows up in light and dark areas of the picture.
The images will also be pretty blurred in the corners, this is because the "optics" on a camera phone are about as bad as they get - they're quite a lot worse than disposable cardboard cameras! :)
The reason for the blocky colours is excessive compression. Check that you have all the quality settings on your phone turned up to highest quality.
But don't get your hopes up, they will always suck i'm afraid. :( Whatever you do, don't bother wasting money on printing them!
Some of the newest high end phones offer auto focus lenses, these are a step up in the world in terms of optics, but the sensors are still rubbish because they're just too small. Don't assume more megapixels will necessarily be better, btw, they will often just exasperate the noise problem.
Hope this helps :-s
Dave
