In Europe we just include the sales tax in the price on the shelf. If the label says £1, I hand over £1. When I'm buying something I don't really care how much of that £1 is tax, how much is going to the shop, how much is going to the producer etc.
The constitutional ban on sales tax is about the only good thing about living in Oregon. Though sales tax is *entirely* regressive, so kind of amazing it flies in the state that gave us Branch Dildonians, Stormfront and kept putting anti-GLBT measures on the ballot for decades.
I used to work in a lab in the Department of Earth and Planetary Sciences at Washington U, therefore I am (extremely) tangentially related to this xkcd and feeling very pleased with myself. (also I wonder if they've figured out why their site is crashing this morning...)
The Apollo Guidance Computers used metric units internally, and converted to "English" units for display... so really there was no excuse for losing the Mars Climate Orbiter over this crap 30 years later. Source: http://www.doneyles.com/LM/Tales.html