ho trovato questo quì:

<?

################################################## #######
# DailyPic #
################################################## #######
# #
# Created by: http://www.free-php.net #
# #
# This script and all included functions, images, #
# and documentation are copyright 2003 #
# free-php.net (http://free-php.net) unless #
# otherwise stated in the module. #
# #
# Any copying, distribution, modification with #
# intent to distribute as new code will result #
# in immediate loss of your rights to use this #
# program as well as possible legal action. #
# #
# #
################################################## #######

// Modify the Following Variables to fit your Website.
// To use simply include potd.php within any php page with the include function.
// For your images you must name them according to date 2003-12-01.jpg would be december 1 2003 image.

$date = date("Y-m-d");

// URL to Fullsize Images.
$image_url = "http://www.free-php.net/demo/DailyPic/photos/";

// Path to Fullsize Images
$image_dir = "/home/www/codemunkyx/www/www.free-php.net/htdocs/demo/DailyPic/photos/";

// URL to Thumbnail Images.
$thumb_url = "http://www.free-php.net/demo/DailyPic/photos/thumbs/";

// Path to Thumbnail Images.
$thumb_dir = "/home/www/codemunkyx/www/www.free-php.net/htdocs/demo/DailyPic/photos/thumbs/";

// Default Thumbnail if no image is available for Today
$default = "http://www.free-php.net/demo/DailyPic/photos/default.jpg";

// Image Extension for Your Pics
$ext = ".jpg";

$photo = "$image_dir/$date" . $ext . "";



if (file_exists ( $photo)){

echo "
<div align=center>
[img]$thumb_url/$date" . $ext . "[/img]

<font size=2>powered by: Free-PHP.net</FONT>

</DIV>
";

} else {

echo "
<div align=center>
[img]$default[/img]

<font size=2>powered by: Free-PHP.net</FONT>

</DIV>
";
}




?>

però implica il fatto che debba nominare le img con le date... dandomi una img di default in caso non ci sia.

più o meno è questo.
solo il fatto dele img...