<form action="http://services.snipshot.com/" accept-charset="utf-8" method="post" enctype="multipart/form-data">

  <input name="snipshot_input" value="http://static.flickr.com/28/96398551_3d6988fe71.jpg" />

  <input name="snipshot_callback" value="http://www.imagehousing.com/upload.php" />

  <input name="snipshot_output" value="fileupload" />

  <input type="submit" />

</form>