They participated in the live music event of the year, helping to raise millions for the victims of Hurricane Sandy, but the musicians who took the stage for last night's (Dec. 12) 12-12-12 Concert for Sandy Relief at Madison Square Garden didn't limit their donations to time and music.

Many of the stars are also participating in a Sandy benefit auction hosted by Charitybuzz and featuring a long list of one-of-a-kind collector's items that range from cool conversation pieces (a saxophone signed by former President Bill Clinton) to drool-inducing pieces of rock 'n' roll memorabilia.

Among the latter list: A Fender bass guitar autographed by Paul McCartney, Bruce Springsteen, Roger Daltrey, Billy Joel, Dave Grohl, Chris Martin, Michael Stipe, Eric Clapton and Jon Bon Jovi, among others; a guitar autographed by the likes of Alicia Keys, Eddie Vedder, Chris Martin, Michael Stipe, Roger Waters, Richie Sambora, Jon Bon Jovi and Bruce Springsteen; and another guitar autographed by Chris Martin, Pete Townshend, Bruce Springsteen, Michael Stipe, Eddie Vedder, Roger Waters and Jon Bon Jovi.

As you can imagine, some of these items are already fetching a pretty penny, even before the final bidding commences. The high bid on the Fender bass, for example, is at $36,000 at press time, and the auction won't close until Dec. 20 -- so, in other words, most of us won't even be able to dream about bidding. But it's still a sweet coda to a fundraising extravaganza that actually lived up to its advance billing -- and it's a pretty excellent way of adding some extra money to the Robin Hood Foundation's coffers.