Soon southbound drivers on I-95 will see a giant love letter to pitcher Cliff Lee as they approach Center City.

"DEAR CLIFF, YOU ARE . . . THIS IS . . . I PROMISED MYSELF I WOULDN'T GET CHOKED UP. WELCOME HOME," a billboard will declare near Girard Avenue.

The "mash note" is the creation of the Greater Philadelphia Tourism Marketing Corp., a private nonprofit funded by the City of Philadelphia, the state, and Pew Charitable Trusts.

Meryl Levitz, president and CEO, was immediately inspired upon hearing Tuesday morning that the former Cy Young winner would return to the Phillies - despite being offered millions of dollars more to play for the New York Yankees.

This wasn't just a feel-good for baseball fans, she knew. It was a major ego boost for the entire area.

"The second that we heard about this, I called my whole staff - I think it was like 7 in the morning - and said we have to do something," she said.

Meanwhile, folks familiar with the agency's "With Love, Philadelphia XOXO" campaign were saying via Twitter, Facebook and emails that local gratitude ought to be all over a billboard.

Staffer Linda Huss came up with the wording.

"What she felt and what we felt is that we were all verklempt, overcome with emotion about it, because it was so wonderful on so many levels," Levitz said.

The billboard, at a cost of a couple of thousand dollars, could be up in about five days and last under Jan. 12, when the agency is committed to kick off its 2011 campaign with another message.

Two other agency billboards - on the Jersey side of the Ben Franklin Bridge and outside Harrisburg - won't get the Lee letter, and neither will the huge sign painted on the side of Madison Square Garden, Levitz said.

Lee reportedly spurned a $160 million, seven-year offer from the Yanks in favor of a $120 million, six-year deal with Philadelphia.

Levitz gushed again about Lee's unintended gift.

"There's no way to evaluate the amount of the publicity that it's worth, and it's just going to keep on coming," she said.

Another World Series win would be nice.

"That's what we do here in Philly," she said. "We make history."

Contact staff writer Peter Mucha at 215-854-4342 or pmucha@phillynews.com.