I don't know about everybody else, but I tend to think about future characters for games I'm in or want to play. So obviously, I'm already kicking around character concepts for Red Markets and I figured I'd share. Feel free to join in and hopefully we can provide some inspiration for Caleb! Since all I really have to go off of is the two episodes of the Game Designer Workshop as far as the world goes, I'm sure some of this may not apply or jive 100%.
So, my main concept thus far has been, effectively, a mechanic-type character. A guy or gal out in the zombie wastes, most likely in a stronghold type settlement or on the border of the wastes who has to sneak out, who scavenges and repairs vehicles for use on the dilapidated highway infrastructure. I can see the knowledge of vehicle maintenance, namely internal combustion engines, broadening out to things like household generator repair and even engine repair on possible robotics, like the BigDog/WildCat drones. Some other things could include monopolizing on the maintenance side to control all of the vehicles in a settlement, renting them out or being the sole retailer. Basically "Hey, I know how to fix these, so if you want to be able use them you gotta talk to me."
That's what I've got right now, gonna try and think of some more ideas or solidify them and then I'll drop 'em here. Once again feel free to share anything you've come up with!