# system is Debian Sarge (postgresql 7.4.7-6sarge1
# pg newbie trying to crate and use users.
# 
# The following were run by the postgres user
postgres@boomtime:~$ createuser tester -A -D
CREATE USER
postgres@boomtime:~$ createdb -O tester testdb 
CREATE DATABASE
postgres@boomtime:~$ echo "ALTER USER tester PASSWORD '1e3';" |psql -d asteriskcc
ALTER USER
postgres@boomtime:~$ echo "ALTER USER tester UNENCRYPTED PASSWORD '1e3';" |psql -d asteriskcc
ALTER USER

# After each of the latter two I tried connecting from my user:
tzafrir@boomtime:~$ psql -U tester -d testdb -W
Password: 
psql: FATAL:  IDENT authentication failed for user "tester"

# the password I typed was '1e3' (without quotes).