In 2008 I had the opportunity to take a career break from work and travel the east coast of Australia. During which time I took close to 3000 pictures of my adventures. An idea I had always had in mind was to create one big image using the smaller photos as tiles.
After a few failed attempts I cheated, but the effect still works. All of my images were resized as a batch job within Photoshop and arranged in a grid. The image that I wanted to use which in this case was one just south of Byron Bay was then pixelated to be the same size as my photo grid. Once placed over the top it creates a pretty clever effect.