Something like Sphinx but for SQL, so we could document table structures and relationships in a series of web pages.
A colleague mentioned PostgreSQL Autodoc
This is a utility which will run through PostgreSQL system tables and returns HTML, DOT, and several styles of XML which describe the database.
As a result, documentation about a project can be generated quickly and be automatically updatable, yet have a quite professional look if you do some DSSSL/CSS work.
It allows specifying schemas and tables, and can even process comments on objects in different markup languages (e.g. markdown) using specified translating executables.