In lieu of pockets or a functional billfold or wallet, the use of one's anus as a recepticle for storing important items. Mainly implemented by members of penal colonies.
Q: "Hey brah, how did you get all of those Zebra cakes in past the guards?"
A: "Um, duh, I just stuck'em in my jailhouse wallet, next to the Swedish Fish and the Choco Tacos. The Choco Tacos are a bit melty, but damn are they exquisite!"
Q: "Listen, broheim, how can I get a copy of the new season of Entourage up in this joint?"
A: "Yo, you should talk to Todd, that guy has the 'George Costanza' of jailhouse wallets."