Extra files required during backup...

I have reviewed the online documentation for PostgreSQL 7.1 for
backup/recovery. This covers the backup of the tables and their contents.
For my backup I wish to include as much as possible to limit the
consequences of a complete failure. From reviewing the archives I have
found the following should also be saved:

data/pg_hba.conf

Does the WAL requiring backup as well? Are there other config files which
require backup?

Thanks

Ashley