I found an accessory of iphone, that will be very useable when taking photos specially during night time.
iFlash LED Camera Flash
- Color Option: Black. Attaches to iPhone/iPod 30 pin and no batteries required
- "Torch" lightsource for better photo and video (light stays on when "on" button is pressed). Use it as an emergency flashlight
- Simple On/Off Button and no apps needed. Push button to turn on and off
- Works with iPhone 4, 3GS, and 3G
- Brightness: 15 cd, Color Temperature: 5000K Viewing angle: 60 deg.