GRANT SELECT ON DATABASE

Hello,

I would like to have a "view only" admin role with SELECT ONLY  rights on the whole database.

Our largest Database has more than 50'000 tables with a few hundreds added/deleted per day...

The link in this Post leads to a php error.
http://archives.postgresql.org/pgsql-sql/2006-05/msg00023.php

Can someone points me to the script, or is there a better approach to create such a role ?

Thanks,

Marc Mamin