Last year in the Transcontinental Race at least one rider came to grief when he broke some spoke(s) and didn’t have spares. I always have six spokes with me (2 for the front wheel, and 2 for each side of the rear wheel) as well as a Fibre-Fix emergency replacement spoke. Of course I also have Stein mini-cassette tool for removing the cassette. A few have commented what a hassle it is to carry spokes so I thought I’d share my solution: your seat tube.
As long as you have not cut the seat tube too short, there is sufficient room to store your spokes.
I cut some foam so it is of a slightly larger diameter than my seat tube. I rubber band together the spokes and insert them through one piece of foam with the curved ends at the top. I then put them part way into the second piece of foam.
I insert the top foam into the seat post and push it up with a spare spoke. Then I insert the bottom end. Once done they are firmly in place—hopefully never to be needed—and you are ready to ride.