Here's a sample request for smugmug.images.get:

<?xml version="1.0" encoding="iso-8859-1"?>
<methodCall>
 <methodName>smugmug.images.get</methodName>
 <params>
  <param>
   <value><string>asfd97241ljasfd97243ljsfd</string></value>
  </param>
  <param>
  <value><int>645</int></value>
 </param>
</params>
</methodCall>

Here's a sample response to a smugmug.images.get call:

<?xml version="1.0" encoding="iso-8859-1"?>
<methodResponse>
<params>
 <param>
  <value>
   <array>
    <data>
     <value>
      <int>17833</int>
     </value>
     <value>
      <int>17834</int>
     </value>
    </data>
   </array>
  </value>
 </param>
</params>
</methodResponse>

<?xml version="1.0" encoding="iso-8859-1"?>
<methodResponse>
 <fault>
  <value>
   <struct>
    <member>
     <name>faultCode</name>
     <value><int>4</int></value>
    </member>
    <member>
     <name>faultString</name>
     <value><string>invalid user</string></value>
    </member>
   </struct>
  </value>
 </fault>
</methodResponse>