This project aims to calculate the ranking between users depending on their User Points.
It is integrated with Views. You could access the results by Views and you could setup for each user point category a View which limits the ranking between users to a specific subset of all users. This allows you for example the ranking of user groups. See also for that Organic Groups.
The result are stored for later us. It is also possible to get rankings from previous ranking iterations.
This module is similar to User Points Top Contributors.
This module is only developed for Drupal 7. For Drupal 6 you could use User Points Top Contributors.