the fastest way to load 1m rows in postgresql

There have been several posts on how to load 1m rows into a database in the last days:

Variations on 1M rows insert (1): bulk insert
Variations on 1M rows insert(2): commit write
Variations on 1M rows insert (1): bulk insert - PostgreSQL
Variations on 1M rows insert(2): commit write - PostgreSQL
Variations on 1M rows insert (3): TimesTen

In this post I'll focus on how to prepare a PostgreSQL database for bulk loading in more detail.