Add another module has been recently updated with another new time-saving feature; you can now display “Add another” tabs on certain node types. I’m also taking the time to think of what else can be done to make the usual node creation workflow easier for end users.
I’ll be looking for suggestions on how to improve the UI and workflow of node submissions and add another module as focus turns to version 2.x. 2.x will released for Drupal 6.x and 7.x in the next month; and will move the workflow settings to the content type edit pages, rather than a separate settings page. The 7.x version will also include a “Save and Add another” button, somewhat similar to submit again, and include integration with node clone.