A key feature in Drupal is being able to create plugins/modules that create their own blocks, chunks of functionality that can be placed anywhere on the page by using the blocks/regions configuration or panels. If you do happen to create your own, bear in mind that while you automatically gain the features of the mail blocks table, you do not gain access to the boxes table, so you have to create your own body content block. Just thought you should know. And yes, this fact has just dawned on me. Doh.