I did a short camera comparison between the iPhone 3GS and 4 vs. the Samsung Galaxy S i9000. Unfortunately, the weather was cloudy all days I had the three devices. My conclusion: the SGS made the sharpest pictures, but the iPhone 4 is often - but not always - better regarding exposure and colors. In general, the iPhone 4 is my winner, followed by the SGS. The 3GS' camera is still good, but on the 3rd place in my comparison.