// ==UserScript==
  // @name          Show Flickr NSID
  // @namespace     http://www.dopiaza.org/flickr/greasemonkey/
  // @description   Display user's NSID
  // @include       http://www.flickr.com/*
  // @include       http://flickr.com/*
  // ==/UserScript==
  
  var imgElements = document.getElementsByTagName('img');
  
  var buddyIconPattern = /^http:\/\/static.flickr.com\/\d+\/buddyicons\/(.+).jpg/;
  var blockheadPattern = /^http:\/\/www.flickr.com\/images\/buddyicon.jpg\?(.+)// Just ignore this one - it's used when you hover over an user's icon
      continue;
    }
  
    // Check to see if this is a buddy icon image
    var src = img.getAttribute('src');
    var result = buddyIconPattern.exec(src);
  
    if (result == null)
    {
      // Try the second version, just in case they have no buddy icon set
      result = blockheadPattern.exec(src);
    }
  
    if (result != null)
    {
      var nsid = result[1];
  
      // We want the first containing tag that isn't an <a> tag
      var container = img.parentNode;
      while (container.nodeName != null && container.nodeName == 'A')
      {
        container = container.parentNode;
      }
  
      var node = document.createElement('span');
      node.appendChild(document.createTextNode(nsid));
  
      node.style.fontSize = 'xx-small';
      node.style.color = 'grey';
  
      container.appendChild(node);
    }
  }