Good point. I guess there would be some other uses for it, for instance....if you have a huge image to download, and you want the client to "get something right away", instead of having to wait for the entire image to arrive. Or maybe there could be some "watermarking uses", where you could put small different watermarks in each tile image. Or maybe use it as a "Concentration" style game, where you display what's behind each tile, 1 tile at a time.

Who knows? I saw this question asked on the perl.beginners maillist, and I thought it was something I would like to have in my toolbox.