Photos.get

The Photos.get returns all visible photos according to the filters specified.
You send:

http://api.facebook.com/restserver.php?method=Photos.get&api_key=YOURKEY
&session_key=YOURSK&call_id=123&sig=MD5HASH&v=1.0
&subj_id=USERID
&format=XML

To find all photos tagged by user USERID. You can similarly find all photos in an album (aid) or in a list (pids).
It returns

<?xml version="1.0" encoding="UTF-8"?> 
<photos_get_response xmlns="http://api.facebook.com/1.0/" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:schemaLocation="http://api.facebook.com/1.0/ http://api.facebook.com/1.0/facebook.xsd" 
  list="true">  
  <photo>  
    <pid>34585991612804</pid>  
    <aid>34585963571485</aid>  
    <owner>1240077</owner>  
    <src>http://ip002.facebook.com/v11/135/18/8055/s1240077_30043524_2020.jpg</src>  
    <src_big>http://ip002.facebook.com/v11/135/18/8055/n1240077_30043524_2020.jpg</src>  
    <src_small>http://ip002.facebook.com/v11/135/18/8055/t1240077_30043524_2020.jpg</src>  
    <link>http://www.facebook.com/photo.php?pid=30043524&id=8055</link>  
    <caption>From The Deathmatch (Trailer) (1999)</caption>  
    <created>1132553361</created>  
  </photo>  
  <photo>  
    <pid>34585991612805</pid>  
    <aid>34585963571485</aid>  
    <owner>1240077</owner>  
    <src>http://ip002.facebook.com/v11/135/18/8055/s1240077_30043525_2184.jpg</src>  
    <src_big>http://ip002.facebook.com/v11/135/18/8055/n1240077_30043525_2184.jpg</src>  
    <src_small>http://ip002.facebook.com/v11/135/18/8055/t1240077_30043525_2184.jpg</src>  
    <link>http://www.facebook.com/photo.php?pid=30043525&id=8055</link>  
    <caption>Mexico City, back cover of the CYHS Student Underground 1999.</caption>  
    <created>1132553362</created>  
  </photo> 
</photos_get_response>