add-this-to-indivudual-archive.html

<div class="other-entries" style="display:none">
  <div class="other-entries-header"></div>
  <ul class="other-entries-links"></ul>
</div>

other-entries.html

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script type="text/javascript">

$(document).ready(function() {
var blogId = '6a00d8341d3fee53ef0168e7ff9ed6970c';
var assetId = TPToolbar.asset_xid; // haha. found it.
assetId = assetId || $('.entry').prop('id').replace('entry-', '');
var url = 'http://api.typepad.com/assets/' + assetId + '/categories.json?max-results=1';
$.ajax({
  url: url,
  success: function(data) {
      if (!data.entries || data.entries.length < 1) return;
      var categoryLabel = data.entries[0];
      var url = 'http://api.typepad.com/blogs/' + blogId + '/post-assets/@published/@by-category/' + encodeURIComponent(categoryLabel) + '.json?max-results=4';
      $.ajax({
          url: url,
          success: function(data) {    
              $(data.entries).each(function(i, entry) {
                  if (entry.urlId === assetId) return;
                  $('<li/>')
                      .append(
                          $('<a/>')
                          .prop('href', entry.permalinkUrl)
                          .text(entry.title)
                       )
                       .appendTo('.other-entries-links');
                  if ($('.other-entries').is(':hidden')) {
                      $('.other-entries-header').text('other posts categorized "' + categoryLabel + '"');
                      $('.other-entries').show();
                  }
              });
          }
      });
  }
});

});

</script>