enhancement to pg_dump: supress columns

I have a situation where I need to hack pg_dump not to dump columns with
a particular name.  If this is of interest to the community I can spend
a little extra effort and work up a patch.  I'd be curious to see if
anyone else thinks this is worthwhile.

Why would I want to do this?  I use a global sequence for a database
wide unique identifier for purposes of locking (to hook into the user
lock module).  This works great but our clients frequently like to make
copies of data for testing purposes and a dump/reload into a separate
schema makes a copy of the generated identifier in the database.

Basically, I need a field to revert to default in a dump/reload cycle.
A command line switch to pg_dump seems the easiest way to handle this.
A specialized domain qualifier which prevents the column from being
dumped is perhaps more elegant but more work.

Merlin