I recently made my first cron contrib module for Drupal, DB Maintenance. Since the DB Maintenance OPTIMIZE TABLE query locks the database tables it queries, I don't want just anyone to access cron.php anymore.
In closing the feature request to add Atom feed options for blogs in Drupal, I added an option to select how many entries to display in feeds, between 1 and 30 inclusive.
On the last of the 4-day New Year holiday, I got a bit productive and port K2 to Drupal. This work is based on Drupal 4.7 Beta2 codes and was tested only with that version.