Going once....

Matt Damon is putting his black, messenger-style baby bag on the auction block.

Also up for grabs: The beachwood highchair that Julianne Moore's daughter Liv calls her "grown-ups" chair and the Adidas track suit outfit worn by Mariska Hargitay's son August.

The stars are teaming up for the Johnson's Celebrity Hand Me Down Auction, which benefits the March of Dimes, Save the Children, Zero to Three and Baby Buggy, among other charities.

The online auction begins April 29 and ends May 9.

Click here for more details.

Says The View's Elisabeth Hasselbeck (who donated a car seat): "It is important to pass certain things on from one generation to the next.

"I still have a children's bracelet that my mother gave to me, which I will pass on to my daughter one day. There is something priceless about having certain things around you which tell a story."

source: http://www.usmagazine.com/matt-damon-to-sell-his-baby-hand-me-down+