Radical Personal Finance had a podcast where he talked about alternative banking measures. There are parts of the world where people really can't get loans at reasonable rates but they still need large chunks of money from time to time.
In Haiti there is a system called the sol (sp?). Basically every month a group of individuals will all contribute to a pool of money and one of them gets to use the money that month. So every month you pay $100 and then one month a year you have $1200 for that larger project.
Why not just save for 12 months? Frankly it's because someone really needs that money so hoarding it for yourself is not socially acceptable. Plus banks are unreliable and it could be stolen if you just stash it under a mattress.
Obviously this only works for stable, reputable, conscientious persons anyway, so probably not the same people who are likely to take out a tribal loan.
I think they are often called savings clubs.
I had a Taiwanese friend who described the same thing and said it was common in China and in Chinese communities elsewhere in the world. It was intended to provide "enough money to do something with" for each person who received the lump sum.
Initially I wasn't a fan of the idea for two reasons. First, the last person in the rotation loses out on compound interest waiting for their turn. Second, if the first few people who get their payouts drop out of the rotation early or skip a few months later on due to shortage of funds, obviously everyone else just got screwed over. If that happens, the only way they can break even is by recruiting new people and paying the screw-over forward, which is also not good for friendship. So I wasn't interested in starting that kind of group myself and turned the opportunity down. Maybe it comes down to whether or not your friends are more reliable than your other banking options. (I didn't think mine were.)
It turns out that something like this can work in an established community where everybody involved has known and trusted everyone else for a long time, and where nobody is going anywhere and people have more incentive to stick around and contribute after a payout than they have to take the money and run. That requires a pretty solid social group.
There's a variation on this concept, called a "gifting circle", and it's a type of Ponzi scheme. (It kind of picks my butt that people are verbing out the word "gift" these days, and when I consider it's a bunch of frauds doing it in this case, it's even more vexing). Here's a simplified version. A handful of people start the monthly pool, and they're at the head of the line. Let's call it Tier 1. They continue to receive the pooled money each month, circulating amongst themselves, but the money they receive is given not just by Tier 1 people (who aren't necessarily chipping in), but also by people in Tier 2. If a Tier 2 person has brought in at least two other people, she (this nonsense is often marketed to women) can move up to Tier 1. Otherwise she just participates in the giving. Once this happens a couple of times, the new Tier 1 people become true believers who are more effective in generating new Tier 2 joiners than anyone else. Once those people's social network is maxed out, the original Tier 1 people drop out. Eventually the mini-pyramid collapses. It's illegal, and it's mathematically impossible for every Tier 2 joiner to make all their money back. Some versions are more complicated and have more tiers.