Want all the shots you took on your iPhone back on your iPhone? If you create a Smart Album in iPhoto with the criteria of Camera Model is iPhone and set the album to sync to your iPhone in iTunes, all your iPhone images will be sent back to your iPhone in the Photo Library. Once set, it happens automatically. The 3Gs has it's own camera model, so you'll need to add it separately and set the Match to Any.
These photos are optimized to iPhone screen size of 480 by 320 to conserve space. It will save space and speed scrolling and rendering over leaving them on your Camera Roll. Smart Albums are also self policing, so if you delete a photo in iPhoto that's part of the Smart Album, it will vanish from your iPhone too.
Most of the art and photo processing apps export their work by sending it to the Camera Roll. All Camera Roll images start with "IMG_". Provided you don't have another camera that uses this numbering prefix, this will selectively export every image that has been in your camera roll back to your iPhone. This also imports any images that you saved from Mail or Safari on your iPhone
Put Photos Back on iPhone
