I'm no longer the only person on the planet who is pushing for scrapping all taxes and replacing the whole lot with a single flat-rate transaction tax! I've just discovered a US-based site called "TRAN$ACTION TAX". It's very nicely done - and very convincing. Just look at these demonstrations.
And they were using a pretty conservative estimate based on only $500 trillion a year (half of the $1000 trillion that they use as their baseline). That seems pretty low to me, given that the BIS numbers for 2010 showed that transactions in the US were virtually $3000 trillion. Never mind. The principle is right.
Their numbers are based on the idea that there would be a 0.35% tax on both the sender and the receiver, meaning that the total tax would be 0.7%.