Hello,
as it is mentioned in the initial post, there is a similar web part implemented here:
http://devnet.kentico.com/articles/dynamic-jquery-ajax-viewer
By default there is just the Load more button, but by a simple change you can load new items just by scrolling to bottom -> tested
It's actually up to you what calls the method for loading more items, you can fire it by clicking the Load more button, by scrolling, by hovering over an image, by resizing your browser, etc. :)
Best regards,
Jan Hermann