Reba McEntire, Keith Urban, Alan Jackson and Keith Anderson are all taking their clothes off -- for a good cause. The celebrities are among those who have donated autographed articles of clothing to raise funds for Porter's Call, a Tennessee-based organization providing free counseling and support for artists and their families in need.

Partnering with auction website Clothes Off Our Back, more than 30 artists and celebrities, including the Jonas Brothers, Tim McGraw, Sara Evans, Gene Simmons, Billy Bob Thornton and Paramore have all donated one-of-a-kind items. The memorabilia includes signed guitars, concert tickets, CD's and DVD's. There's even a signed Super Bowl XLI football from the IIndianapolis Colts.

The auction runs from Sept. 14 - 30. Click here to place your bids.