The LCS Address Book runs once a day at 1:30am (default). When the Microsoft Office Communicator client logins on, it downloads and caches the address book to your user profile directory.

While, in general, LCS is one of those applications that 'just works', on occasion you need to know that something you've done is working properly. Being able to sync the address book service to and validate the changes on Communicator is very useful.

• On the Live Communications Server where the address book service is running, go to the command line and enter:
  
  abserver.exe -syncNow
• On your local system delete the galcontacts.db from your profile directory, log out of MS Office Communicator and then back in.
  
  C:\Documents and Settings\[username]\Local Settings\Application Data\Microsoft\Communicator\galcontacts.db

So far I have found two reasons to do this.

1. The address book service was crashing and the eye catching yellow diamond was annoying to people. Being able to do this let me validate that it was working rather then waiting until 1:30am was very nice.
2. When implementing IP Telephony integration with Nortel phone switches and trying to get the phone number normalization rules set up and tested.