Hoping to stand out among the clutter, the nets have embarked on another round of viral marketing stunts to launch their fall shows.

Travelers flying in and out of LAX, for example, can’t help but notice a gigantic ad for CBS’ “The Amazing Race” painted over the roofs of three buildings, all in a row.

“We’re right on an active approach path,” said CBS marketing topper George Schweitzer. “So we’ve gotten plenty of reports from people who have seen it. It organically fit ‘The Amazing Race,’ and we thought it would be a fun thing to do.”

The Eye is also slapping promo messages on thousands of eco-friendly, biodegradable hangers that have been handed out to dry cleaners in New York and Los Angeles.

Created by a company called Hanger Network, the EcoHangers are made of recycled paper and plastic bottle caps, reshaped into hangers with room for marketing messages on the front and back. According to Hanger Network CEO Bob Kantor, the CBS hangers alone will replace more than 17 tons of steel-based wire hangers — which usually end up in U.S. landfills.

“The composition of the dry cleaning marketplace is exclusively adults, with a slight affluent skew,” Kantor said.

In other recent network viral campaigns, ABC let loose a traveling kiosk that gives away free pies in honor of “Pushing Daisies,” while Fox created a mysterious website filled with strange plot-based clues for “Fringe.” NBC, meanwhile, plans to launch several returning shows on Hulu first before the skeins make their return bow over the air.