I agree that 510 users need some kind of better solution for carrying stuff with you. Up to this point, I have been more or less fine leaving my juice, ecig, and pcc in my car while out and about and at work. With winter coming fast though, I will need to be able to take everything with me. I am currently looking for a case that will easily fit in a pocket and will hold my pcc and a fully assembled 510. But that will still probably leave juice on its own, which I'd rather not risk due to possible leaking.
As it stands now, my only decent option is to only bring 1 full ecig broken down in my pcc, which I can charge while I'm not vaping. Then I plan to use a little ziploc bag for my juice to carry in my pocket.
Going off my 510 pcc, it would be easy to make one the same size but as a "drippers" pcc. Leave the battery charging hole, an atomizer hole, then convert the space for 2 carts into a little hole for a 3ml dropper bottle. As it stands now, the cartridge holes in the pcc are little more than worthless to me and probably the vast majority of drippers.