hiding the postgres password - v8.1.0

Hi,

Is there a way to hide or encrypt the postgres password when the postgres
user is required to be the user in a shell script? This way we could have
a function called in a program, and the users could do something with out
actually seeing the postgres user password.

We have tried putting the postgres user password in a perl script, however
when we run the script we get password coming up interactively as the perl
script is running doing a pg_dump or createdb for example.

We want regular users to be able to pg_dump, drop, create, vacuum etc.
Postgres is the owner of our data directory. The group permission are in a
sys - admin group.

Thanks for any feedback,
~DjK