He has also appeared on recordings by The Desert Sessions, Masters of Reality, Peaches, Unkle, Axis of Justice and Sweethead.

"[2] During his cancer treatment, Dean Fertita of Queens of the Stone Age and The Dead Weather filled in on bass.

[2] Long-time friend and collaborator Josh Homme, along with Dave Grohl and John Paul Jones of Them Crooked Vultures, announced a concert at the Brixton Academy in London to raise money for O'Connor's treatment.

[2] On August 12, 2010, Queens of The Stone Age, Eagles of Death Metal, The Last Shadow Puppets and Alain Johannes performed a benefit show at the Nokia Club in Los Angeles to raise funds for O'Connor.

[3] Former Queens of the Stone Age member Mark Lanegan sang four encore songs with the band.