Julia Roberts and her pal Dave Matthews are teaming up again.

Roberts – who joked to PEOPLE in 2005 that she is the Dave Matthews Band's "mascot" – will introduce the group when it performs at the Stand Up for a Cure 2008 Concert Series at New York City's Madison Square Garden on Sept. 10.

"The charity is honored that she will be introducing the band at the concert," says a rep for the event. "Her support will make a huge difference."

The concert will raise money and awareness for lung cancer research.

The last time Roberts worked with Matthews was in 2005, when she appeared in his "Dreamgirl" video. It was her first acting gig after she gave birth to twins Hazel and Phinnaeus, who are now 3 ½. She and her husband Danny Moder had a third child, Henry Daniel, in June 2007. – K.C. Baker