Multiple Address Books In Exchange 2003

Hi

As a company we have now taken on under our group names multiple other companies…
So the GAL with all the contacts in them is no rather big…
I was wondering is there a way of creating seperate address books for all these outlook contacts which are stored in their own OU in AD.

The GAL is close to 500 names and we want say the Global Address Book then an address book for each company,

I have tried creating a offline address book and it wont download so maybe m barking up the wrong tree..

Thanks for any tips
ET