The Web Services Group Manager tool is quite popular. It is so popular in fact that we needed to change how often we recalculate group counts.
When you go to the "My Groups" listing you will see counts next to each group. These counts are now updated once a day, the first time someone views them in a list. Also, if you add, upload or delete members we recalculate the group count. Anywhere we display the group count it is now hyper linked. Just click the count and we will recalculate your total.
We have many more enhancements coming in January for the Group Manager and Email+ tools.