I bought an ostrich leather Atoll case that is cedar lined, including the 2 dividers (holds 3 cigars). Not sure the leather would do well sitting in a humidor all the time. Few ideas:

1. Keep the cedar dividers in the humidor to keep them humidified. That does nothing for the sides, however.
2. Keep a cigar shaped humidification device (beads) in the case. I just got one of these; if I'm only gonna carry 2 sticks, I'll just leave it in, too.
3. Get one of those tough plastic cases that are foam lined and have a little green foam humidifier; just wet it with the 50/50 solution. They come in small sizes; I think I've seen cases that hold 3 or 5 cigars. I also just got a plastic box for about 6 cigars that has a "surgical sponge" humidifier at the top and a little analog hygrometer built in and readable from the outside. Waiting to try it out. Don't think it's cedar lined, though.