Exactly. I'm as much a low-tax advocate as most anyone, but it's never made sense that online (or mail order) purchases should be able to evade sales taxes while physical stores can't.  Especially in the computer age where determining the applicable taxes by shipping address should be relatively easy.

This is an area where the federal govt should probably facilitate a central database where the states maintain their various tax rates/districts/parameters, which all US retailers link to.