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