Drupal 7

The Problem:
Displaying a random image from the image field in a certain node type (where not every node has an image) in a block.

My Solution:
1. First thing is create a view with the following "Default" settings:

Add the following function to the template.php for your theme:

function yourthemename_preprocess_page(&$vars, $hook) {
 if (isset($vars['node'])) {
 // If the node type is "blog" the template suggestion will be "page--blog.tpl.php".
  $vars['theme_hook_suggestions'][] = 'page__'.$vars['node']->type;
 }
}
 
Change the "yourthemename" in the function name to match the name of your theme.

By default, a Drupal 7 image field that is set to contain multiple images, will display all of the images in both the teaser and full node view. While desirable, there is no option when creating a view to only show the first image in the teaser. This can be accomplished, however, with the new Drupal 7 field-level template-hint.

In order do this globally for a field named "field image" the following code in a template file named "field--field_image.tpl.php"

<div class="<?php print $classes; ?> clearfix"<?php print $attributes; ?>>