Synchronizing a Global Address List in an Exchange 2007 Environment
Documentation on how to synchronize GALs in an Exchange 2007 environemnt.
ILM 2007 FP1 provides a solution to synchronize the global address list (GAL) between two Active Directory forests in a Microsoft® Exchange Server 2007 Service Pack 1(SP1) infrastructure. The goal of a GAL synchronization solution is to synchronize users, groups, and contacts from one forest with contact objects to another forest.
Download the paper here.