I began working a couple of days ago on some code to integrate Simpy with Drupal.
The first working draft is here: it has a search block, a tagcloud block and also semi synchronizes with Simpy when the cron.php script is ran. Also, you can view all links which have been tagged with a particular tag (try clicking on a tag in the tagcloud).

However, there's a lot to be done before I release the code to the public. If anyone wants a peak, drop me a line.