More than Caching DNS server

Hi,

I've got a single install of BIND running sweetly after reading this tutorial:

http://linux-sxs.org/internet_serving/bind9.html

It's working as a Caching DNS server.
But now I'd like to use my DNS server from other machine's not just
the machine which is running the dns server.

When I try a Dig from a remote box I get a refused connection.
For example the DNS server is at 64.235.238.29 and I'm wanting to
do a dig from 203.220.112.84 ( that's USA and Australia ).

Is there something simple I need to add to my named.conf file
to enable this feature ?

My named.conf file is almost identical to the one in the above mentioned
tutorial.

Once I have this up OK I'd like to move into setting up a slave dns server.
I really like this software.

Many thanks in advance.
Best regards
Rudi.