At request I've added the cron module to drupal.org. It's named admintools, cause I plan to make more tools for the admin of several drupal installs. So more news will follow soon on that.
A drupal 5 version of the cron module will follow shortly.
You can find the module at: http://drupal.org/project/admintools.
You might want to consider
You might want to consider merging your ideas into one of these two Already existing modules/suites: