Password entry in pgadmin3; pg_hba.conf vs .pgpass. Permissioning issue?

[also posted to Django users Google group]

Hi all,

Can I bypass the need for password entry in pgadmin3 by
changing/locating/permissioning a .pgpass files instead of modifying
pg_hba.conf to 'trust'? pg_hba.conf currently set at md5 for
everything.

1. I can merrily connect to the postgres server on my local ubuntu
machine as user postgres in bash by "su postgres" then "psql".
2. But if I want to be able to use pgadmin 3 GUI without entering a
password I need to do this as my user, andyt and this doesn't work (I
did chmod 600 this file to give rw access to one owner only). This
feels like a permissioning issue but with that chmod 600 restriction
on pgpass I'm not sure how to progress.

I have been messing around with strace trying to figure out the
location of pgpass which is being sought out when I run psql/pgadmin3
but the results are inconclusive. They both (now)seem to be looking in
the andyt home directory. Not sure if this was the case earlier,
sorry! I was earlier placing .pgpass here there and everythwhere, but
in particular /var/lib/postresql.

Grateful for any guidance,

Regards,

Andy

Key file contents:

1 pg_hba.conf:

local   all             postgres                                md5
# local   all             postgres                                trust

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     md5
# local   all             all                                     trust
local    django_db    django_dev                md5
# local   django_db       django_dev                              trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            md5
# host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 md5
# host    all             all             ::1/128                 trust

2 ,pgpass
127.0.0.1:5432:*:postgres:Password@
:5432:*:django_dev:Password@