A few weeks ago, I came across a photo mosaic tool that I couldn’t resist sharing. Image Mosaic Generator creates photo mosaics with a few clicks in just a few seconds. Simply choose a digital picture and the rest is done for you. The only limitation is that you can’t customize the tiled photos within the mosaic. If you want more control of your tiled images, you could try other free photo mosaic software AndreaMosaic.
Image Mosaic Generator can be used as an extension of an art project such as “guess the artwork” art history game or an “I Spy” on the images within the picture.
Update 12/10/12: While searching for photo mosaic creators for a school auction project, I discovered Picture Mosaics. While this is not a free service, based on this review it is an excellent option for high quality photomosaics.