Yesterday we schlepped out to the Brownsville section of Brooklyn because we were promised Jon Bon Jovi working on a Habitat for Humanity house. "Delta Air Lines joins Jon Bon Jovi and members of the Philadelphia Soul arena football team on Tuesday, April 3, 2007, at 1:00 p.m. to participate in a build with Habitat for Humanity-New York City," said the press release (the emphasis is ours), which seemed pretty clear. Bon Jovi! Brooklyn! Together! Yay! But then we got there and discovered the dude merely giving a press conference. Wasn't Jon going to "participate" in that "build"? "You really don't want to see me grabbing a hammer," he said. (Actually, we did, which is why we spent an hour on the D.) "But I'll be happy to purchase them." Sigh. How about Marty Markowitz, also on the scene — was he excited to have a genuine rock star purchasing hammers for Brooklyn? "I can't really tell you I know his stuff," the usually indefatigable borough president said, "but I know people are crazy about him." We should have stayed in midtown. —Jonah Green