Newbie Question, how to grant permissions on all tables in schema/db

Hi guys, I'm wondering what the easy way to grant user/group access on all tables
in a db.  I just migrated about 200 tables from my MySQL database using a cool
migration script, but now all the tables are owned by me in the schema public.

That is all fine and all, but I wish I could run a command like:

grant all on * to group developers;

where developers contain my created users.

is there a way to do this easily?

Thanks in advance!
-Kenji