Convert MS Access DB to PostgreSQL with indexes and cascading update/delete and autoincrement, oh my. Windows Only, it's in Visual Basic.
The Microsoft Access to PostgreSQL converterproject is a PostgreSQL Community project that is a part of the pgFoundry.
The pgFoundry page for the project is at http://pgfoundry.org/projects/msdbtopg, where you can find downloads, documentation, bug reports, mailing lists, and a whole lot more.
