ImageShack Clone is an intuitive and easy-to-use free image hosting solution script. It can be used to share pictures with friends, as well as to post images on message boards.
When you purchase this script, you will receive a download link with a zip file with the complete source code. It is written in PHP and is unencrypted so you will be able to modify it to suit your needs. The code you download will be the exact same code that I use to run the demos.