Working on a project this week I needed a module to allow users to sign up for orientation sessions and automatically close signups when the sessions are full. The signup module for Drupal does this but didn't have the ability to close signups after reaching the maximum number of participants. After a few false starts and simplifying the code I rolled a patch that adds eight lines of code and adds the functionality. The patch uses an unused column in the database so a database change isn't needed (I originally had added a new column but realized that the close_signup_limit column isn't used).