Admin messages system.

Some features:

• Drupal message displayed to users with valid permissions
• A history of such messages
• Ability to hide/close such message
• Some options for the time or login interval when a new message should be displayed

_{Recently I found myself in a situation that I need to inform a couple of people about implementing a new feature or removing an annoying bug on their drupal site. Since sometimes interested person is hard to reach this would be great to have a system that would show (on every page or on certain pages set in settings) a drupal message, but only to chosen people (easy to achieve with drupal messages + permissions).}

Even more - it would be cool to have some short history of such messages in a convenient place. To have the ability to set the number of logins when the message is displayed or the time period as well.

Maybe we could actually extend drupal messages system? Maybe it's achievable using some hook (hook_nodeapi? hook_elements?)? It could use some JQuery script to pop the message up or to bring attention :)

Just my plain thoughts :)