Rob,
According to the PostgreSQL FAQ at
http://www.postgresql.org/docs/faqs/FAQ.html :
and there are ODBC drivers.
See also
http://techdocs.postgresql.org/guides/MSAccess
Otherwise: the dump file is (I'm pretty sure) just a text file
containing a series of SQL commands which create the tables and
relationships and all and then append the data (which is contained in
the script). So if you enjoy munging text it's not a very big deal to
1) extract the "create table" statements, convert them into Jet SQL and
run them in Access to create the tables.
2) create the indexes, relationships, etc in the Access UI
3) parse the data out of the relevant parts of the file into text files
that Access can import.
I had a quick look on the web. There's Access VBA code at
http://docman.sourceforge.net/home_html/projects/sql/exportSQL3.txt
which unfortunately exports an Access database to a SQL script.