How can I make this XML gallery snippet prettier?
There's a lot of duplication to get src, name, and so on. Simply use $.map:

var properties = $.map(["src", "name", "date", "desc"], function(id) {
  return xml.getElementsByTagName(id)[d].childNodes[0].nodeValue;
}


You can then use properties[0]. Not sure how I could return an object with the correct keys as simply as this. Maybe something like

var properties = {}
$.each(["src", "name", "date", "desc"], function(i, name) {
  properties[name] = xml.getElementsByTagName(name)[d].childNodes[0].nodeValue;
}

Don't forget any var
Create img using this less error-prone technique:

var img = $('&lt;img&gt;').attr({'alt': properties["name"], 'src': properties["src"]});