Deny creation of tables for a user

[Pascal Cohen <pcohen@xxxxxxxxx>]

Hello
I am playing with security in Postgres
And I would like to have a database that can be managed by a given user 
that could do almost anything but I would also have a user that can just 
handle what is created.
I mean she could insert, update delete rows but not create tables.

I did not find a way to revoke such thing. Is it possible ?

Thanks!