Here's the solution that worked for me:
On the upload form:
HTML Code:
<input name="s_userfile1" type="file" id="image" class="form" onchange="document.getElementById('imageName').value=this.value;" size="25" maxlength="50" />
<input name="upload" type="hidden" id="imageName" class="form" /> On the form processor:
PHP Code:
<?php
$vis_email = $_POST['vis_email'] ;
$image = $_POST['imageName'] ;
//Format Email
$email = "my email address here";
$subject = "Testimonial Form";
$headers = "From: $vis_email\r\n";
$headers .= "Content-type: text/html\r\n";
$upload .= "$image";
//Send Email
mail($email,$subject,$message,$headers,$upload);
?>