Recently a client asked if it was possible to brand communicator and I vaguely remembered the deployment guide explaining how to do this. Anyway, here are the registry settings for branding the Communicator:
[HKEY_LOCAL_MACHINESOFTWAREMicrosoftMessengerServiceServiceProviders{83D4679F-B6D7-11D2-BF36-00C04FB90A03}Branding"company name"]
"PROVIDERNAME"="Microsoft Office Live Communications Services by Company Name"
Use Regedit to add these entries. Once they are added, do an export so they are easily applied to other systems.