Inspired by an old ActionScript effect. This lightweight (1.2kb minified and gzipped) cross browser javascript file is free of any other dependencies. It's 100% javascript too.

it sounds quite simple to achieve, take the end pixel and stretch it the length of a div, and repeat for the whole image.

You can give it a try here and here.

I will be implementing this feature on my site in the near future - I like it that much