Rome's Spanish steps have always been a seductive spot, but never quite like this. On the facade of the church sitting at the top, a billboard featuring huge glossy lips advertises Glam Shine lipstick--maker of such colors as Diva and Siren. Now the Pantheon is looking for a piece of the action: it is among 50 well-placed historical sites whose aging facades are up for grabs to the highest advertising bidder.

The ads are part of a campaign by Rome's city planners to raise funds for critical renovations to historical monuments. Because the billboards are placed on scaffolding and therefore considered temporary structures, they are allowed under Italy's longstanding ban on out-door billboards in the city center. The initiative--which began several years ago as a modest attempt to balance the city budget--has been a huge financial success. Even temporary city-center posters can go for hundreds of thousands of euros--more than enough to pay for a major renovation. The rotating ads that will eventually blanket the Pantheon, for instance, are expected to cover not only the 700,000 euro cost of cleaning the ancient structure but a dozen additional renovation projects as well.

The problem, say Romans, is that the ads are getting out of hand. Good taste--muted diamond-jewelry ads prevailed at the start--has given way to greed. Now in-your-face billboards advertise everything from neon cell phones and flashy red Fiats to giant shoes and Versace dresses--all in the name of fixing up old buildings and filling city coffers. Indeed, Rome collected more than 13 million euro in ad taxes and permits alone last year--which does not go back into building projects. Now officials are wondering if some of the proposed renovations are really just a scam. "They are restoring palazzos just so they can put up advertising," says Adriano La Regina, superintendent of archeology for the city of Rome. "There's been a series of tremendous abuses." La Regina believes scaffolding stays up longer than necessary or is erected when works don't require it--such as when interiors are being revamped. And the size of the scaffolding keeps growing. By law, posters should not take up more than 15 percent of the total scaffolding area. So project managers merely double or triple the amount of scaffolding needed; the result is ads--like the 200-square-meter Glam Shine billboard atop the Spanish Steps--larger than most homes in urban Rome.

Authorities are responding to the criticism. Rome Mayor Walter Veltroni has urged restraint, calling for suggestive posters to be replaced with more demure images. One massive cosmetics poster of a model in a pink hat was considered so offensive that authorities deemed it a health risk, since it distracted drivers and blocked light. The Rome city council recently renewed an old regulation proclaiming that ads can't be "invasive" and must be "compatible with the building on which they are displayed." Beginning Sept. 1, advertisers will have to submit mock-ups to the city council for approval. Until then, visitors to Rome are likely to find their views obscured. "Normally, you'd see characteristic medieval architecture in hues of terra-cotta orange," a guide in the Campo dei Fiori recently told her American tour group. "But for now you see a giant neon green Vespa."