Here is an article from USA Today:
Although no precise estimates are possible, as much as $1.6 trillion in North American wealth is likely held in offshore accounts, according to a 2005 report by the Tax Justice Network, an international group opposed to tax avoidance.
A network of brokers, accountants, attorneys and other providers is increasingly promoting offshore trusts and accounts as a way to avoid lawsuits, creditors and, in some cases, federal and local taxes in the USA. Riding the rapid expansion of the Internet, some parts of the mini-industry are making tax-avoidance techniques — once mainly offered to high-net-worth individuals in private conferences — available online to average Americans.
In addition to Swiss and Liechtenstein, here are some places (not all of them) in Caribbean:
Belize. Caribbean nation has eight banks, one insurance company, 23 trust companies and 38,741 registered offshore corporations.

British Virgin Islands. A territory of the United Kingdom, it has more than 500,000 registered offshore corporations.

Cayman Islands. United Kingdom territory is home to more than 500 banks and trust companies, 7,100 mutual and hedge funds.

Isle of Man. A crown dependency of the United Kingdom, the Irish Sea island is home to 171 offshore service providers.

Panama. Central American nation has 34 offshore banks and about 350,000 offshore companies.

St. Kitts and Nevis. A federation of two Caribbean islands that has one offshore bank, 50 trust and company service providers and 15,000 offshore corporations
And so on and so forth…..
According to a GAO report, since 2002, the number of American entities reporting a Cayman Island bank account has jumped from 2,677 to nearly 8,000. Suspiciously, investigators traced more than 9,000 American entities that had registered in the Caymans to a single office building.
Is that building one of the largest buildings in the world to have 9,000 American entities? With 69,000 total population of Cayman Islands? Average seven Cayman Island residence work for one American company in one building alone? How many more buildings in Cayman Island? May be one Cayman Islands residence own one American company? May be 10 companies? How many more locations/places/countries in Caribbean as tax heavens for USA?
I am using Cayman Island as an example: Cayman Island is 100.4 square miles, estimated of population in 2008 is up to 69,000. How can they have 500 American Banks? More than 7,100 mutual fund companies? Hundreds of thousands people open their credit cards in Cayman Island? Tens of thousands companies registered in Cayman Island…..
Accenture, the old name is Anderson Consulting, used to be part of one of the biggest accounting firm called Anderson Accounting, and one of most respected computer consulting company is a Bermuda company. Hillary and Bill Clinton have over $53 million in their Cayman account? And so on and so forth….

There are too many lawyers, accountants, salesperson, and Bull Shxt artists