You can create a collage online at Costco, but they only do the grid ones. I wanted one that looked a little more random so I created one on Picasa. You can download Picasa for free. Then I saved it to my computer and uploaded it to Costco online and had them print it out in a 12x12 print. $2.99!!
The clock worked, but was missing hands. I had a hard time finding hands to fit since it was a different brand than the replacement ones I was looking at. So I bought a clock kit at Michael's with black hands to use for this project.
Place the photo on the clock and find the center point. Then mark it and cut it out so that the clock kit will slide through. I was lucky that it was already pre-drilled for the previous clock kit. Then I traced around the clock and cut out the photo.
After that dried, I applied another coat of mod podge to the top of the clock and then assembled the clock kit and black hands. The clock kit was super easy to add and had great instructions. You could make a clock out of ANY hard surface. Just drill a hole (if it doesn't already have one) and you are good to go!