It's just a restatement of cryptoanarchy. The problem with the theory is, unless the majority of your commerce is done through a black or gray market, it is still trackable by the government, and has gotten more and more trackable as technology advances.
Credit card companies and banks are not likely to offer truly "untracable" accounts to consumers anytime soon, especially with the war on terrorism going on.
Large employers are highly centralized and there are a finite number of payroll companies, so income tax can be extracted at those choke points by the gubmint before it reaches your wallet.
Untracable cash is more likely going to be used to avoid sales taxes.