Set a block region from the block edit page
In Drupal 7 you have the option to set the region of the block within the block's edit page.

I haven't seen a module for this for Drupal 6 let alone earlier versions. I would strongly recommend upgrading to Drupal 7 for this feature and the plethora of other desirable features of Drupal 7 compared to it's predecessors.

I hope that helps...