"Obviously recycling is the one thing you can do. Trying to conserve water and turn the lights off, just being conscious of it — you don't have to make yourself miserable trying to do it but every little bit helps," says Nick Lachey, host of NBC's a capella group competition "The Sing-Off," which has its season premiere Sept. 19. "Not taking anything away from the previous season, but the groups are so talented, I can't even imagine how hard the judges' jobs will be," he says, noting that a cappella "more than any other kind of music takes a lot of practice and dedication before you go out there. You have to practice, practice, practice, and hone your sound."

The 98 Degrees alumnus' solo career is coming off the back burner, as he's gearing up to record a new album. "It's a long time coming for me and I'm excited to get back to it. It's tentatively called 'The Soundtrack Of My Life,' but that isn't a done deal yet." He has fond memories of his boy band days, acknowledging, "I certainly wouldn't be doing anything I'm doing now if it hadn't been for that opportunity." A reunion might happen someday, he confirms. "We talk about it all the time and I wouldn't be surprised if we didn't get back together at some point," he says.

In July, Lachey married actress Vanessa Minnillo, who'll host the next edition of ABC's "Wipeout." "We're a two-host household now," he says.

"This is just another element of what I already do in the business," says Shawn Stockman of his role as a judge on "The Sing-Off," serving on the panel with Ben Folds and Sara Bareilles (replacing Nicole Scherzinger, who defected to "The X Factor"). The Boyz II Men singer still does 150 shows a year with the group, so he's juggling TV tapings with his tour schedule. The trio is also readying a 20th anniversary album of ten new, ten re-recorded tracks that will be released exclusively at Wal-Mart in October. At home, he uses eco-friendly cleaning products and recycles. "We try to do our part," he says.

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