According to an article from CNET, a number of online retailers (including Target, Marshal Fields, and others) will begin charging sales tax on orders filled after Feb 2, 2003.

All of this action is part of an agreement created last year between 38 states and the District of Columbia to provide an amnesty for the retails who start collecting taxes in all 39 jurisdictions.

It appears that, since these taxes are the same as the existing local and state sales taxes in the areas in question, they are not covered by the congressional moratorium on additional (or discriminatory) taxes charged by states on online purchases.