It's all based on CSS. The Random Images plugin returns an unordered list of objects, so to make it horizontal you need to make your list-style: none and float: left the <li> components (most likely with a fixed width).
To show the randome pic horizontaly remove <br/> tag from the line #65 in random-images.php page:- ------------------------------------------- original line #65 is: ------------------------------------------- <a href="<?php echo generate_url('picture', $id); ?>" title="<?php echo addcslashes($cap_or_name, '"') ?>"><img class="random-images-thumbnail" src="<?php echo generate_thumb($path, $id); ?>" alt="<?php echo $name ?>" /></a><br/> ----------------------------------------------------------------------- find this line and remove <br/> from the end of line : ----------------------------------------------------------------------- Enjoy