Originally Posted by SebaKL
One trick I learn long time ago, using Galaxies, is to hold steady after taking the shot. Just because the shutter is came on, it apparently doesn't mean the camera is done. Ever since I figured that one out, all the photos are pretty good.
This is sound advice.
I have also noticed that moving the phone after the shutter sound will result in blurring. Since the shutter sound is completely artificial (unlike a real SLR) it appears that the sound occurs slightly too early so moving the phone just after the sound means its moving while the photo is being taken.