It's trivial to set Adobe Reader to open outside the browser. Just clear the "Display PDF in browser" check box on the "Internet" panel of the preferences.

Multiple resolutions in one file was one of the features of the FlashPix format that was introduced way back in 1995. There was a complete ecosystem offered by major tech companies, including free browser plugins that provided zooming and as-needed download. FlashPix failed to gain a significant foothold and is rarely used today. There's a little bit of information on the format at http://en.wikipedia.org/wiki/Flashpix, and a format specification at http://graphcomp.com/info/specs/livepicture/fpx.pdf.

While Deleware and Orgeon may not have a state sales tax, there are probably other sales taxes that Borders will collect from at least some residents of those states.

U.S. sales taxes are levied by states, counties, cities, and other entities. For example, in the Dallas, Texas area there's typically a state sales tax (~6%), a city sales tax (~1%), and a sales tax for regional mass transportation (another ~1%). The overlay of all these different taxes results in many, many different tax rates across the country.

The difficulty of correctly calculating these taxes and transferring the funds to the taxing entities used to be one of the arguments against mandating the collection of taxes by mail-order and on-line retailers. It seems like people have since figured out how to do that.