NEW ORLEANS -- You might not think it would make his top 10 list of things to do in retirement, but on Saturday, David Letterman was in New Orleans for a good cause.

He volunteered with the organization Habitat for Humanity, doing service work in New Orleans East.

Kate O'Leary, who was at the event, says that Letterman volunteered with the organization last year as well.

"He likes to help out with projects like that, and keep it on the down low," she said.

Last May, Letterman retired from his nightly talk show, "Late Show with David Letterman" on CBS, which he hosted for nearly 25 years.