David, All, I think Jignesh's solution is the correct one. It doesn't give the developer accounts any permissions they didn't already have: the PostgreSQL binaries are executable by any normal user. It just adds convenience and management to each developer's ability to run a "private instance".
The only question is: how difficult would it be to do through SMF? And should there be a separate service for "private instances", or should this all be the generic service? I'd argue for the former, because there's a big difference in the results, and I wouldn't want to see an admin getting confused about which PostgresQL they were running because they forgot which shell they were in. --Josh