I've always felt a special fascination for mosaics. From Roman tile compositions to current digital collages, I think they're an awesome artistic expression.
That's why I was so happy when I found Andreamosaic.
It requires having a large collection of photos to use as tiles, that's true. Fortunately the installation file already includes a pack of 500 sample photos that produce excellent results.The program's interface is quite dull; in fact it's simply a gray window with too much text on it. But the mechanics are easy to understand so you'll be creating your own mosaics in no time!
Plus, the program includes a 20-page manual that explains everything thoroughly. Just remember that the more tiles you use, the longer it will take to generate the mosaic and the larger the final file will be.