Here is an example of using the interface plugin to make drupal's administration tasks a bit easier. This module allows you to modify the primary links for your site by simply dragging and dropping menu items. Click here to see an example.

I was introduced to this through work I was doing on porting certain Wordpress themes over to drupal. The look and feel of the average Wordpress theme has always in my opinion been far better than the average drupal theme - of course you may disagree, which I find surprising (not the fact that you may disagree) given that it is far easier again in my opinion to develop a theme for drupal compared to Wordpress. Anyway I digress.

After seeing this in a configure block module for a certain wordpress theme I followed it to an implementation in drupal for the mysite module http://drupal.org/node/101471#comment-203584 and then I jumped in to see how I could work on something similar.