PostGIS PL/pgSQL Add-ons - Readme http://github.com/pedrogit/postgisaddons
The PostGIS Add-ons attempt to gather, in a single .sql file, useful and generic user contributed PL/pgSQL functions and to provide a fast and Agile release cycle.
A quick description of every new function can be found at the beginning of the postgis_addons.sql file. A detailed description precede each function definition.
Installation:
Simply run the postgis_addons.sql file in your PostgreSQL/PostGIS database. PostGIS must already be installed.