Dump only part of a DB

Hi,

pg_dump can be used to dump an entire database, or just a single
table.  Is there a way to make a consistent dump of more than one
table, but less than all of the tables in the database?  Doing a bunch
of single-table pg_dumps isn't really an option, because some tables
may change during the dumps, leading to constraint violations if we
try to restore them.

Rationale:  We have an application that makes a nightly dump of its
database.  There's one particular table that tends to be large, but happily
it's not critical if it's lost -- no real need to back it up.  So we'd
like to back up everything except that one large, non-critical table.

Regards,

David.