diff -Naur spritegen-0.1a1/includes/css-sprite-gen.inc.php spritegen/includes/css-sprite-gen.inc.php
--- spritegen-0.1a1/includes/css-sprite-gen.inc.php	2008-01-26 06:25:19.000000000 -0500
+++ spritegen/includes/css-sprite-gen.inc.php	2008-02-23 16:52:07.000000000 -0500
@@ -64,6 +64,7 @@
       }
       
       public function ProcessForm() {
+      
          require('validation.inc.php');
          
          $aFieldsToIgnore = array(
@@ -77,7 +78,8 @@
             'classpre',
             'tagspost',
             'fileregex',
-            'use-transparency'
+            'use-transparency',
+            'use-checksum'
          );
 
          $aRules = array(
@@ -287,12 +289,20 @@
             if (!is_dir(SPRITE_DIR)) {
                mkdir(SPRITE_DIR);
             }
-         
+
             $sOutputFormat = strtolower($this->aFormValues['imageoutput']);
+            $this->bChecksum = !empty($this->aFormValues['use-checksum']);
+            
             $this->sTempSpriteName = SPRITE_DIR.uniqid('csg-').".$sOutputFormat";
             $this->WriteImage($oSprite, $sOutputFormat, $this->sTempSpriteName);
             imagedestroy($oSprite);
             
+            if ($this->bChecksum) {
+               $newName = SPRITE_DIR . 'csg-' . hash_file('md5', $this->sTempSpriteName) . ".$sOutputFormat";
+               rename($this->sTempSpriteName, $newName);
+               $this->sTempSpriteName = $newName;
+            }
+            
             $this->bValidImages = true;
          }
       }
diff -Naur spritegen-0.1a1/templates/home.php spritegen/templates/home.php
--- spritegen-0.1a1/templates/home.php	2008-01-26 06:25:19.000000000 -0500
+++ spritegen/templates/home.php	2008-02-23 17:07:01.000000000 -0500
@@ -63,8 +63,9 @@
 
       <?php echo $functions->TextInput('bckground', $translation->Get('form.label.background-colour'), '', 7, $translation->Get('form.hint.transparency'), true); ?>
       <label for="use-transparency"><?php echo $translation->Get('form.label.use-transparency'); ?></label><input type="checkbox" name="use-transparency" id="use-transparency"<?php if (!$formPosted || isset($_POST['use-transparency'])) echo ' checked="checked"'; ?>>
+      <label for="use-checksum"><?php echo $translation->Get('form.label.use-checksum'); ?></label><input type="checkbox" name="use-checksum" id="use-checksum"<?php if (!$formPosted || isset($_POST['use-checksum'])) echo ' checked="checked"'; ?>>
       
-      <?php echo $functions->SelectInput('imageoutput', $translation->Get('form.label.sprite-output-format'), $imageTypes, '', ''); ?> 
+      <?php echo $functions->SelectInput('imageoutput', $translation->Get('form.label.sprite-output-format'), $imageTypes, '', ''); ?>
    </fieldset>
    <fieldset>
       <legend><?php echo $translation->Get('form.legend.css-output-options'); ?></legend>
diff -Naur spritegen-0.1a1/translations/en.txt spritegen/translations/en.txt
--- spritegen-0.1a1/translations/en.txt	2008-01-26 06:25:19.000000000 -0500
+++ spritegen/translations/en.txt	2008-02-23 15:48:27.000000000 -0500
@@ -31,6 +31,7 @@
 form.label.vertical-offset = Vertical Offset
 form.label.background-colour = Background / Transparency Colour \# (optional)
 form.label.use-transparency = Use Background Colour for Transparency
+form.label.use-checksum = Use Checksum of Contents in Filename
 form.label.sprite-output-format = Sprite Output Format
 form.label.css-prefix = CSS Prefix (optional)
 form.label.filename-pattern-match = Filename Pattern Match (optional)