BACK IN THE '70s, a popular poster said something like, "Imagine if schools had enough money and the military had to hold bake sales."

And while peanut allergies and health concerns have led to bans on school bake sales in New York and other communities, the poster's main point underscores how the scarcity of funding for schools has been with us a long time - and will probably always be.

City Council, and Blondell Reynolds Brown in particular, are to be commended for thinking of creative new ways to fund the schools. We think that one idea - keeping bars open an hour later to capture more drink tax - frankly is less harmful than the idea of allowing advertising on school buses.

Reynolds Brown's proposal would allow the district's 1,250 buses to carry ads. It follows a number of districts around the country that have legalized such advertising, including New Jersey's action last year. Her office claims that it would generate $5 million over four years.

This may, on the face of it, seem like an easy $5 million - though since that projection is based on a single line in a newspaper story quoting an advertising executive, it's more appropriate to call it a rumor - but that's the problem: Like casino gambling, this advertising is a too-easy path that ignores deeper consequences. Casino gambling has so far paid off in spades for the state, but to the lament of many, including the families of problem gamblers. But the moral compromises we make when we pimp our students out to the highest bidder are just the beginning.

Reynolds Brown says that certain kinds of ads, for cigarettes and liquor, would be restricted, though the First Amendment could limit those restrictions. And what about other supposedly "safe" products that could also be problematic, like advertising for soda and sugary snacks? The district will have to create a structure to be arbiter of such decisions.

But the real danger is blurring the boundaries between civic life and commerce. One anti-commercial advocate, Gary Ruskin, points out that "turning the school and the school bus into an advertising delivery mechanism corrupts the integrity of public education. It transfers the moral authority of school administrators and teachers to corporate advertisers."

Advertising can corrupt the message that public education is one of society's core values that should be free from commercial influence. Of course, such high-minded thinking doesn't help fill the budget gap. And the fact is, we believe that corporations should play a bigger role in supporting public education, since they stand to gain from a better-educated workforce.

But school-bus ads are not the way to go. Besides, once we accept ads on the outside of buses, it's an easy leap to put them inside the bus, then inside the classroom. Council should let this idea run out of gas.