I've seen live compilations of 'Hot Space' and now 'A Night At The Opera' be uploaded; I think it's good to see this.
One of my other favourite artists is Springsteen and one of his messageboard sites (SPL), the bootleg collectors have compiled a set of CD's comprising of the BEST live version of the album tracks.
Basic information can be found here http://www.stoneponylondon.net/live-collection
The example of the process of deciding songs can be found here http://www.spl-messages.net/ubbthreads/showflat.php?Cat=0&Number=269113578&an=0&page=0#269113578
Wouldn't it be a great idea if the collectors from this board could get together and start compiling these sets?