Perhaps you've heard of the Google Apps Directory Sync? If not, you probably haven't been using it yet. It's a utility that allows businesses and schools to easily transfer their information from a LDAP user directory to Google Apps. You still keep your data in the LDAP server, but Google Apps now has access to it so you don't have to build an entirely new user account directory.
If that sounds good to you and you want to know more, Google has created an in-depth webinar/tutorial that walks you through the process of transferring all the information over to GADS. Before you start, you're going to need a few things though.
GADS only supports LDAP servers like Microsoft Active Directory, Lotus Domino and most other generic LDAP servers. As far as operating systems go, it only supports Windows XP Service Pack 2, Windows 7, Windows Server 2003/2008, Linux and Solaris version 8 or above. It's worth noting that GADS doesn't support Solaris on x86 systems.
Perhaps you don't feel that GADS is for you. You're doing just fine with your current set-up even if Google Apps is widely respected enough to be used by Canadian and U.S. government entities. Well, if you still aren't sold, here's the key benefits of using GADS according to Google:
Synchronizes your Google Apps user accounts to match the user data in your LDAP server.
Supports sophisticated rules for custom mapping of users, groups, non-employee contacts, rich user profiles, aliases, calendar resources, and exceptions.
Performs a one-way synchronization. Data on your LDAP server is never updated or altered.
Runs as utility in your server environment. No machine outside your perimeter accesses your LDAP directory server data.
Includes extensive tests and simulations to ensure correct synchronization.
Includes all necessary components in the installation package.
Before you go running off to start using GADS, Google has posted a handy tutorial that will walk you through the transfer process. It clocks in at a meaty 25 minutes so get out some note taking material just in case you miss anything.