Disable hyperlink on image

you can use a theme function to do this: theme_image_attach_body() and theme_image_attach_teaser() would be what you'd want to override.

take a look at http://drupal.org/node/55126

find the image_attach.module in modules/image/contrib and
in it:

function theme_image_attach_body($node) {
  $img_size = variable_get('image_attach_size_body_'. $node->type, IMAGE_THUMBNAIL);

  if ($img_size != IMAGE_ATTACH_HIDDEN) {
    drupal_add_css(drupal_get_path('module', 'image_attach') .'/image_attach.css');

    $image = node_load($node->iid);
    if (!node_access('view', $image)) {
      // If the image is restricted, don't show it as an attachment.
      return NULL;
    }
    $info = image_get_info(file_create_path($image->images[$img_size]));

    $output = '<div style="width: '. $info['width'] .'px" class="image-attach-body">';
    $output .= l(image_display($image, $img_size), "node/$node->iid", array(), NULL, NULL, FALSE, TRUE);

and change the last line as:

$output .= (image_display($image, $img_size));

Can you explain this further, please?

I added the function to my template.php file, renamed it to reflect the name of the theme I'm using. What specifically do I need to change here? Sorry for such a newb question, but I appreciate any help you can provide.

Thank you.

you're removing the l() call (which creates a link) and its parameters. you can read about l() here: http://api.drupal.org/api/function/l/5

Thank you so much.