By default, the Contact List in Communicator Mobile is sorted alphabetically. If you created groups using Communicator on your desktop, the groups are sorted alphabetically and the contacts within each group are also sorted alphabetically. You can also view contacts in your Contact List according to their presence status by using the Group by Availability feature. When you group contacts according to their availability, contacts that are not currently available or whose presence status is unknown are listed separately, at the end of the Contact List.
To group contacts by availability
In the Contact List, tap Menu > Options.
Tap the General tab, and then select the Group contacts by availability check box.
If you want to sort contacts using the default Contact List view, repeat these procedures.