drop PW

I have created a new 8.3 version DB and populated it. A specific user
of this database (george) has been setup with a password, so that every
time I use psql or some other utility, I need to supply this password.
So I want to drop the password authentication. I tried rerunning
createuser (and just pressing Enter when prompted for the new password),
but it complains that the user already exists. I can't drop the user
because this user owns the DB and all the tables. My postgresql books
are all for 7.x, and suggests altering the pg_shadow table (which seems
risky to me). I tried:
ALTER USER george PASSWORD '';
and that looked like it succeeded, but running psql again prompted me
and when I just hit Enter, it complained that no password was supplied.

So how do I turn off being prompted for a password for george. (I am
aware of the security risks...)

Mark