Database replication under Postgres

Hello all, I wonder if anyone could help me.

I'm currently working on a project where it is essential that we have some
kind of replication of our production database.  I've found a number of
'near' solutions (e.g., doing a piped 'COPY IN/OUT' using psql - one
local and one remote - from a simple shell script) but this doesn't
'synchronise' the data, it just piles ALL the data from one database into
the other.

I've also looked into setting up rules on a table to NOTIFY me of an
insert|update|delete and then have a program that queries the difference
between the two databases and synchronises them accordingly. This is ok to
a point but is not particularly elegant or efficient.  Basically I was 
wondering if anyone knows of a better way of doing it or if someone has
written a tool for automating replication with Postgres.

If we were replicating data from one table to another in the SAME DATABASE
it would be easy to set up a rule such as:

CREATE RULE itbl1 AS ON INSERT TO tbl1 DO (INSERT INTO tbl2 
values(new.i));

Ideally, I suppose what I am after - and I dare say I'm hoping to much - 
is a simple solution that says the same as the above rule but where
"tbl2" is a table in a remote host's database.

I would be really grateful to hear from other users' experiences with any
form of replication/synchronisation under Postgres.

Thanks in advance.

Paul M. Breen
Computer Park Ltd
Email: pbreen@computerpark.co.uk