Main Index Pablo Honey The Bends OK Computer Kid A Amnesiac Hail to the Thief In Rainbows The King of Limbs A Moon Shaped Pool Thom Yorke Jonny Greenwood Ed O'Brien Colin Greenwood Philip Selway
A line of the song appeared in the 'scrapbook' section of (I couldn't find the original png image file in the scrapbook anymore):

negatives for cash
The official 2006 Radiohead calendar contained a page which featured related lines (click to enlarge):
'Bangers'n Mash' was one of the titles that appeared on the blackboard the band used during two weeks of rehearsals from september 19th to 30th 2005. At the end of that session, Colin posted a picture of this board on Dead Air Space on september 30th, unfortunately (and probably intentionally) in rather low resolution, so that some of it can't be deciphered:
'Bangers and Mash' was notably absent on the second blackboard posted on march 8th 2006, which contains songs considered for the upcoming tour. Nonetheless it was played regularly throughout that year:
On December 5th 2006, Thom posted this on the official message board:

On June 15th 2007, Nigel posted a video on Dead Air Space, that showed the playback of a reel of assembled tape snippets, which were cut out during the editing process.
The reel contains 4 fragments from the finished recording of 'Bangers'n'Mash':
Click here for a more detailed description of this reel, including all 20 snippets in isolation.
On April 2nd 2008, the band performed 'Bangers And Mash' at Maida Vale studios in London for Nigel Godrich's From The Basement programme:
Following the European Tour for In Rainbows, Radiohead held a survey among fans in July 2008 to gather data regarding the carboon footprint of the tour.
On July 17th participants received a link to the download of a soundboard recording of 'Bangers And Mash' from the first gig of the European Tour in Dublin on June 6th 2008:
'Bangers and Mash' was not performed during the touring for The King of Limbs.