Index: wp-admin/includes/media.php
===================================================================
--- wp-admin/includes/media.php	(revision 18057)
+++ wp-admin/includes/media.php	(working copy)
@@ -366,23 +366,25 @@
  * @since 2.5.0
  */
 function media_buttons() {
-	$do_image = $do_audio = $do_video = true;
+	$do = array('image' => true, 'audio' => true, 'video' => true);
 	if ( is_multisite() ) {
 		$media_buttons = get_site_option( 'mu_media_buttons' );
 		if ( empty($media_buttons['image']) )
-			$do_image = false;
+			$do['image'] = false;
 		if ( empty($media_buttons['audio']) )
-			$do_audio = false;
+			$do['audio'] = false;
 		if ( empty($media_buttons['video']) )
-			$do_video = false;
+			$do['video'] = false;
 	}
+	$do = apply_filters( 'media_buttons_media_types', $do );
+	extract($do);
+	
 	$out = '';
-
-	if ( $do_image )
+	if ( $image )
 		$out .= _media_button(__('Add an Image'), 'images/media-button-image.gif?ver=20100531', 'image');
-	if ( $do_video )
+	if ( $video )
 		$out .= _media_button(__('Add Video'), 'images/media-button-video.gif?ver=20100531', 'video');
-	if ( $do_audio )
+	if ( $audio )
 		$out .= _media_button(__('Add Audio'), 'images/media-button-music.gif?ver=20100531', 'audio');
 
 	$out .= _media_button(__('Add Media'), 'images/media-button-other.gif?ver=20100531', 'media');