What is your favorite common phone book?

what is you favorite common phone book? for all the phones, (i use cisco and grandstream)
and is easy to use to the final user?

and… a question: is possible to use the simple asterisk phonebook incluided on the freepbx, to usea as a common phone book to all the phones? (the phones have to read this phone book)

sorry of my english, i’m spanish and i think that my english is not very good.

anybody use a common phone book on the freepbx?

i need a recomanation only…