In hawala, sums large and small are sent halfway around the world on a handshake and a code word. Records of transactions are kept just until the deal is completed. Then they are destroyed. No cash moves across a border or through an electronic transfer system, the places where authorities are most likely to spot or record the transaction. The sender does not have to provide his name or identify the recipient. Instead, he is given a code word, which is all the recipient needs to pick up the same amount of cash from an associate of the original trader. The transaction can occur in the time it takes to make a couple of phone calls or send a fax.
In many places hawala (which means 'trust' in Arabic) is illegal, but it is hard to stop, and more convenient than using legal banks and such, relying on a known web of trust. Authorities believe that Osama Bin Liner and the hijackers who committed the WTC attacks made use of hawala.
Oddly enough, nobody has registered eHawala.com. Though there is a hawala.com, registered in Falls Church, Virginia. They don't have a web site, though.