Password protection?

Quick query -

I can't figure out how to password protect an username.

e.g. I'm trying to create

user: rasputin
password: obvious

createuser seems to work fine;

createuser -d -A -P -e

but psql never asks for the password, it just lets me in.

i.e.  createdb -U rasputin babel

creates a database without prompting for a password.

I'm obviously missing something incredibly simple.

Postgres 7.0.3, all connections are local.

I tried tweaking the 'local' lines in

~postgres/data/pg_hba.conf (changed 'trust' to 'crypt')
and restarting postmaster, but that blocked the postgres user too!

I reckon it's that file I need to edit, but how?
(Or how do I set an initial password for the user 'postgres')

Cheers.

--
Rasputin
Jack of All Trades :: Master of Nuns