I found this recently while looking up some information related to my military service.  It may be useful to some of your customers

 military.com com offers a free address changer service.

The fastest and easiest way to tell everyone your new address. The service will notify:
The United States Post Office
Frequent Travelers Clubs
Magazines
National Organizations
Catalogs
Home Security Companies
College Alumni Associations
Monthly Clubs

Click here to sign up http://military.moving.com/Moving_and_Planning/addresschanger/

 Further military relocation information can be found @ http://mcguiremilitaryrelocation.blogspot.com/