Outside of Great Bridge and Red Hat, there are many companies that provide consulting services to the PostgreSQL community. The following is a small list of consultancies providing commercial support for PostgreSQL.
Command Prompt, Inc. is located on the web at: http://www.commandprompt.com/
Command Prompt is a Linux managed services and PostgreSQL support company. They provide Linux and PostgreSQL support, including custom programming featuring PostgreSQL, C++, PHP, Perl, and their own LXP application server for PostgreSQL.
Command Prompt, Inc, you might have noticed, also authored this book.
Cybertec Geschwinde & Schvnig OEG is located on the web at: http://postgres.cybertec.at/
Cybertec provides training courses, support, consulting, and cost effective high-end systems. Cybertec services the German speaking region (Austria, Germany, Switzerland).
dbExperts is located on the web at: http://www.dbexperts.com.br/
dbExperts offers training courses, specialized support for development and commercial products for PostgreSQL. dbExperts is located in Brazil and provides services in the Portuguese language.
PostgreSQL, Inc. is located on the web at: http://www.pgsql.com/
PostgreSQL, Inc. offers support for PostgreSQL, database hosting, and promotional materials.
Software Research Associates is located on the web at: http://osb.sra.co.jp/
Software Research Associates offers a range of services to aid customers with Open Source software based systems. Support from this company is also available in Japanese.