I carry a couple of Fibre Fix repair spokes instead of the cassette remover and spokes, I haven't used them yet but they pack small and weigh little. On bikes with STI/Ergo shifters I also carry a downtube lever, again something I haven't used, but purchased after three hilly days on a single speed after a minor fall buggered a shifter.
http://www.sjscycles.co.uk/fiber-fix-emergency-replacement-spoke-prod20155/
http://www.sjscycles.co.uk/fiber-fix-emergency-replacement-spoke-prod20155/