A friend of mine just released a converter of .dbf files to PostgreSQL, under the GPL license. He writes:
This document provides a step by step instruction how to convert DBase II, DBase III+, DBase IV and (to some extent) FoxProV2 files to PostgreSQL. This solution is based on the excellent Simple DBase SQL by Michael Lecuyer.
UPDATE 2013-05-18: The link above is still valid.