Heroku Postgres Now supports Postgres 9.1 and introduces new features and a freemium version for developers.

New features include:
• Postgres 9.1
• Data clips
• hstore
• Direct database access from psql or other libpq clients.
• Support for most pg commands in the Heroku command line client.
• Visibility through the web interface at postgres.heroku.com.
• Support for many databases connected to one application.