I have a client that is concerned about their users having access to the GAL. Is there a way to hide it completely from the end user without resorting to HMC?

This would help you to segregate Default GAL with set of users while they access their mailbox with outlook as well as with OWA... Address Lists in Exchange 2007 (Part 1) http://msexchange.org/articles_tutorials/exchange-server-2007/management-administration/address-lists-exchange-2007-part1.htmlAmit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com