This is my (quite crazy compared to what we have) tax rewrite for the US. It is inspired in part by Ron Paul.
My solution is to pass a constitutional amendment that prevents the federal government from collecting any fees, taxes, donations, or seized goods from any citizen. Also in that amendment would be a provision that income may not be taxed by any state, county, or other local government.
A sales tax is specifically allowed, as the primary method for states and governments to get money.
Revenue for the federal government would be provided by the state governments alone, with some specifications for how much each state pays, whether that is by population, a percentage of that state's revenue, or such. Aside from certain declarations of emergency by a state, federal monies would also not be allowed to benefit a state or other local government.
And that is the plan. It is very revolutionary, and quite different from what we have now.
Gone is the IRS, along with the huge accounting businesses that have sprung up to help people to interpret that crazy tax code. Also, the federal government would not be able to take money from people in a state and then hold that money hostage pending that state from passing certain kinds of laws (55 speed limit, 21 drinking age, 0.08% BAC to name a few).
The government has to get money somehow, and a sales tax by the state and other local governments is all that is left. This would mean that it doesn't matter where your income comes from, nor does the government at any level need to know. Nor do citizens that don't run a business have to even collect and remit to the government any taxes at all, since the current sales tax infrastructure would take care of that.