How do I list all schemas in PostgreSQL?

When using PostgreSQL v9.1, how do I list all of the schemas using SQL?

I was expecting something along the lines of:

SELECT something FROM pg_blah;

To lists all schemas, use the (ANSI) standard INFORMATION_SCHEMA

select schema_name
from information_schema.schemata;

More details in the manual

alternatively:

select nspname
from pg_catalog.pg_namespace;

More details about pg_catalog in the manual

StackExchange Database Administrators Q#40045, answer score: 435