I don't think multiple tax jurisdictions and rates are confined to the US alone. Seems to me that last time I was in BC I was paying both a Provincial and National VAT.
I am glad to say I live in one of the few States without a sales tax. That, of course, throws a wrench in the idea of federal legislation to equalize sales taxes, since such legislation would clearly infringe on State's rights. Were the feds to impose a State sales tax I might have to explore moving to a State with no income tax ;)