Pix Of The Day (POTD) script allows you to automatically display a new picture everyday without any uploading or editing of HTML pages. Just use SSI or javascript call to display the picture anywhere you want.
Random Image is a small script that can randomly display your images stored in a folder. You specify which image extensions to search for in a specified folder. Everytime visitor comes to your page, a new image is displayed. It can be used by SSI; however, if your server does not allow the use of SSI you can use it with a javaScript call