PostgreSQL Group Roles – Understanding and Managing

This is not a "group by" question. I am struggling with permissions in postgres because I apparently don't understand how group roles work. Searching for this on SO has proven difficult because I get buried in questions about group by, which isn't the problem.

I have been using postgres to manage a series of research projects. These databases are not connected to any web front-ends. I import all of the data from CSV. For the past few months, I have been the only user. This has worked really well. I am the db owner and nobody else needed to care. Recently, I built a complex database containing data from several sources. Because of the number of tables involved, each data source has its own schema and I have created a series of convenience views to make it easier to work with these various data sets. These schemas should be read only to all users, except for myself.

This project requires several other people to have access to this database. Each user has a username / password and an individual schema, where they can work without cluttering up the public schema. I want to be able to control access to the schemas such that the schemas holding the original data are "select only" to the other analysts. However, I want the all other schemas in the database to more or less function like the public schema in terms of access. These schemas exist for logical structure, not to control access. I want everyone to be able to read/write/create/drop/etc. in these other schemas that don't hold the original data.

Unfortunately, postgres roles are rather tricky or I've been rather slow to understand. Setting this up has been tricky as new tables are created by different users. I keep having to re-run the grant access commands manually as we add new tables.

The alter default privileges seems to imply that I can do this using group roles, but when I have tried to do so, other users were unable to access new tables. This seems to imply that I can set up group roles that will allow me to manage access, but I haven't succeed thus far:

You can change default privileges only for objects that will be created by yourself or by roles that you are a member of.

I'm just looking for some help to understand how to best utilize group roles to control access to schemas/tables/views in Postgres. I don't want to have to manually grant access every time I add a new table, or worse, manually grant access every time I add a new user. I would prefer to be able to add a new user to a larger group, that controls the access.

Based on comments given, I have tried to use the following syntax. In this example, there are two users, achoens (me) and mrubin (a co-worker). I can log in as both users. As achoens, I run the following:

create schema foo;
alter default privileges in schema foo grant select on all tables to public;
select 1 into foo.test;

I log off as achoens and log in as mrubin. I then run

select * from foo.test;

Which returns a permissions error. In this instance, Postgres 9.1 is running on a windows server but I tried it on my home server running Ubuntu and got the same results. I like postgres but this makes it much harder to use in a collaborative environment without just making everyone into an administrator, which I would prefer to not do.

I also edited the above syntax to reference against a user group called analyst, which both achoens and mrubin are members of. No difference. User mrubin was unable to read the silly little one row table.