OK, putting ads on school buses and in textbooks was one thing, but plastering them on notes sent home to parents is almost comically intrusive. But it's something parents in Salem, Mass., will have to put up with, as school officials have voted to allow it as a fund-raising measure for their penurious district. The ads will take the form of business-card-size placements on the back of permission slips and notices sent home for parents to sign. That's not as obnoxious as it could be. It's just depressing that schools, and sometimes individual teachers, see no better solution to their impecuniousness that a desperate hunt for ad dollars. Finding local companies to sponsor detentions would be interesting, though.