All Aboard: A Tribute to Johnny Cash
album title: All Aboard: A Tribute to Johnny Cash
artist: various (compilation)
released: October 21, 2008 (Anchorless Records)
track: "Ballad of a Teenage Queen," performed by The Dresden Dolls
more info: "All proceeds from this record will go to the Syrentha Savio Endowment, a non-profit providing assistance to underprivileged breast-cancer patients." (Anchorless Records)
 

Ghosts I - IV
album title: Ghosts I-IV
artist: Nine Inch Nails
released: March 2, 2008 (The Null Corporation)
tracks: Brian Viglione's "jivin' and wailin'" is on tracks 19 and 22
 

Ooky Spooky
album title: Ooky Spooky
artist: Voltaire
released: July 31, 2007 (Projekt Records)
track: "Stuck With You," featuring Amanda Palmer
 

DRIVE XV: A Tribute to Automatic For the People
album title: DRIVE XV: A Tribute to Automatic For the People
artist: various (compilation)
released: 2007 (Stereogum)
track: "Everybody Hurts," performed by Amanda Palmer and Cormac Bride
more info: Listen and/or download here.
 

album title: Brainwaves
artist: various (compilation)
released: November 17, 2006 (Brainwashed Recordings)
track: "The Lovers," performed by Amanda Palmer and Meredith Yayanos
more info: Wikipedia page
 

So Divided
album title: So Divided
artist: ...And You Will Know Us by the Trail of Dead
released: November 14, 2006 (Interscope Records)
tracks: "Life" featuring Amanda Palmer on piano

"Eight Day Hell" featuring Amanda Palmer on piano

"Witch's Web" featuring Amanda Palmer on piano and vocals
more info: wikipedia page
Amazon listing
 

.2 Contamination
album title: .2 Contamination
artist: various (compilation)
released: 2006 (Failure to Communicate Records)
track: "Life on Mars" (David Bowie cover), performed by The Dresden Dolls
more info: Failure to Communicate's website
Amazon listing
 

Fresh Off Boat
album title: Fresh Off Boat
artist: Golem
released: August 22, 2006
track: "Warsaw Is Khelm," featuring Amanda Palmer
more info: Amazon listing
 

A Dark Cabaret
album title: Fresh Off Boat
artist: various (compilation)
released: 2006 (Failure To Communicate Records)
track: "Coin-Operated Boy," performed by The Dresden Dolls/td>
more info: wikipedia page
Amazon listing
 

Stange Music for Strange People (Volume 1)
album title: Stange Music for Strange People (Volume 1)
artist: various (compilation)
released: 2006
track: "Backstabber," performed by The Dresden Dolls
more info: EmilyStrange.com
 

Pornos and Razorblades
album title: Pornos and Razorblades
artist: Hierosonic
released: 2005
track: "Circus Freak Love Triangle," featuring Amanda Palmer
more info: Amazon listing