[OT?] permissions

im having a heck of a time here

if this is off topic please redirect me

lemme explain

im trying to set up a 'one user one database scenario'
while still maintaining the postgres user account

here is the prob
how do i set it up so i can do this
iut would seem this would work in the pg_hba.conf:

local all trust postgres
host all 127.0.0.1 255.255.255.255 trust postgres

but then anyone can
psql -U postgres
and get in without password!
so i try

#local ident not avail! right?
host all 127.0.0.1 255.255.255.255 ident postgres

and get this
psql: No pg_hba.conf entry for host localhost, user postgres, database postgres
even though it says 'all'

is this right?
or should i have to allow access on a database per database?

thoe other problem is that

local mydb password passwd
host mydb 127.0.0.1 255.255.255.255 password passwd

would allow anyone with access to postgres to connect to this db

how would i strengthen this and still keep using the password ?

one would think there should be an extra option on this of user to connect

like

local mydb password passwd myuser
host mydb 127.0.0.1 255.255.255.255 password passwd
myuser

or is there a way to grant perms on a database?
i could seem to do that !
so there seems to be a little problem in the clarity on how to do this
i looked over the docs and bruce's book and i could seem to get it together

any help
most appreciated

--
Psychiatry enables us to correct our faults by confessing our parents'
shortcomings.
-- Laurence J. Peter, "Peter's Principles"