I have lost count of all the threads that say "sorry for crappy iphone pics", when in fact they should be saying "sorry I can't be bothered supplying you with a decent picture".
I am not starting a big fanfare for Apple stuff, but you can take amazing pictures with an iPhone and its not that difficult. I am sure that other camera phones work quite similarly but I've only had an iPhone so can't comment.
1. Put the thing you want to take a picture of in a nice place. A dark cellar or shed is no good. You'd struggle with a proper camera in those situations anyway. Outside is best, but at least turn all the lights on and don't take a pic from the shadow side.
2. Hold the phone still. Again, this is the same as a normal camera. If you're waving it around or holding it with 2 fingers then it's never going to be steady. I sometimes use a broom handle as a makshift tripod if I'n taking pics inside, but I do that with a normal camera anyway.
3. Tap the screen where you want the main focus to be. If you tap it somewhere where the image is a bit dark it will automatically increase the exposure and lighten the image if it's needed, so try a couple of taps to get the best result.
4. Take picture.
99% of my pics on here have been taken with my iPhone 4. Ok some of them aren't great but thats because of my laziness rather than the device I am using.....
So pleae, make the effort, as a blurred dark photo is nearly worse than no photo at all...
iPhone pics I have done:
Taken in a dark cellar
Taken in a darkish kitchen:
Outside at dusk: