I recently promoted a long time sandbox module of mine to a full project available through Drupal.org. The "Exclude Node Author" module prevents authored on/by information from being displayed on a per node basis. Instead of hiding author information for an entire content type, can be hidden on just a single node. Designed for sticky nodes (but can be used anywehre) providing information about a page rather than used as content. This module was originally designed for internal use for the ARISE Child and Family Services Inc staff intranet, they funded the original development of the module. The "Exclude Node Author" module was based on the excellent Exclude Node Title module, currently maintained by id.tarzanych, fizk and gabrielu.
When enabled, the module provides a checkbox (shown in the image here) on all node edit forms (all content types). If the user has appropriate permissions to edit and use Exclude Node Author, they will be allowed to check the box and prevent the authoring information from being displayed when the node is rendered. It is important to note that this module only acts on nodes rendered through the standard node rendering processes, and will not affect Author information being used in other contrib modules like metatags or views (fields).
Future enhancements to this module are planned. I intened to enhance the admin settings UI to allow for finer grain control of which content types the module is available for. Feature requests, bug reports, and patches are always welcome, see the issue queue at on the Exclude Node Author project page on Drupal.org