But however clever a money laundering scheme might be, the aim is always the same: disguising the paper trail of transactions from dirty money to clean.
Usually this happens through layers of "shell companies" - firms which exist only on paper, perhaps with directors whose sole responsibility is to be a front man with a sinecure - anonymous bank accounts, bearer shares, over-or under-invoicing on general trade deals and a range of other techniques.
But what if you could avoid the paper trail altogether?
That could prove to be the real difficulty in tracing money back to those responsible for the US attacks - especially if Bin Laden really is behind them.
The secret lies in an alternative banking system hundreds of years old, known in India as hawala and in Pakistan - and Afghanistan and the Middle East - as hundi.
According to Prof Barry Rider, director of the Institute of Advanced Legal Studies in London and an expert on financial crime, the trust-based hundi system is entirely normal, and prevalent wherever there is a South Asian or Middle Eastern diaspora.
"Say I'm working in the UK and want to sent money back to a village in Pakistan," he said. "I could get a bank transfer, but that's going to be at the official exchange rate. And what good will it do my family in a village with no bank?"
Instead, he says, you find the hundi broker - often a local small businessman - give him the money, and after a short time his contacts back home will deliver the money, at the black market rate, in local currency and minus a handling fee, to your relatives.
No paper trail, no fuss. And no money ever crosses a border - discrepancies in the two-way flow are settled up at the end of the month, or perhaps every half year.
Impenetrable
Which makes it perfect for drug traffickers, for example - Afghan drug smugglers have used Pakistani hundi brokers for years.
More recently, the Chinese "chop" system - where no money changes hands at all, and instead "tokens" (often now passwords sent by email) are used as the equivalent of letters of credit for gold or diamonds deposited with trusted third parties - has been used by the Afghan drug and arms trade.
And many observers believe the chances are such a widespread, impenetrable system is certain to be used by the likes of Bin Laden.
"No intelligence organisation - except the Directorate of Revenue Intelligence in India, perhaps - has ever effectively cracked the system," says Prof Rider.
"You could count the number of successful penetrations on the fingers of one hand."