http://www.interpol.int/Public/FinancialCrime/MoneyLaundering/hawala/default... Interpol has an interesting article on Hawala. It's written from a US-centric perspective, which unfortunately includes asymmetry in the transactions, so they miss out on the importance of net settlement in making correspondent banking systems work, and it does look at hawala as somewhat of a quaint leftover from before modern banking systems, rather than understanding that the roots of European banking systems were the same thing. And of course, since it's written by Interpol as opposed to a newspaper or a college economics professor, its real interest is use in criminal transactions. But it does give a good picture of part of the hawala system, some cultural flavor, and some reasons that hawala is popular - flexibility, speed, lower costs than official banks, arbitrage around official exchange rates, and avoidance of regulations that inhibit transactions. It's a worthwhile read.