As is currently, it might help people knowing that you administer this module in Administrative Blocks (Drupal 6: admin/build/blocks). Configuring the block will allow you to specify settings like which content types can be included in the popup window.

If possible, it would probably be good to separate the administrative configuration for the module into a separate area. More specifically, if you're using the admin_menu module, it would be good for the Site Configuration menu to have an option for Bookmarklet. This would seem more intuitive. Also, I knew how to add the jquery postMessage script to my theme, but others may not. It would be nice if there were a Drupal module to handle this dependency.