Since then, following suggestions on the feedback forum I've implemented a few new features. What I've noticed is the ease at which these features where added, thanks to the quality of the Zend Framework.
Along with adding icons for up votes, there's now a little star icon to add snippets to your favourites, easily accessible from your user page. A little sprinkling of dojo and these are added via AJAX.
Snippets can now be edited by the creator and a revision history is kept.
Using a simple implementation of the Longest common subsequence problem, you can also view diffs of the revisions.
Lastly there's the search engine, built on top of Zend_Search_Lucene. This took a little more work, but the results were worth it. I hadn't realised how powerful the Lucene query language was until now and I'm very impressed with the implementation.
As you would expect, traffic has slowed down considerably since the initial burst, but there's still a bit of steady traffic there and I hope people keep coming back to visit now and then. As for going forward, I think I'll add a field to allow contributors to specify which zend framework version their snippet was tested or is compatible with, then look a little more at the scoring system.