Copying few tables from one database to another

Hello,

what is please the command to copy tables from 1 database
from another and is it possible at all without using pg_dump?

I'm trying to migrate 4700 users from phpBB 3 to Drupal 7
and have few custom tables in the "phpbb" database
which need to be copied over.

Using CentOS 5.5/64 bit + PostgreSQL 8.4.7

Thank you for the hints into the right direction
Alex