Restricting delivery to certain states/countries

This is something to consider for PC.  Every state has its laws about what is allowed to be sold or not.  For example some seeds or plants may be restricted because they endanger the local flora.  Furniture has to be fire retardant in some states while others don't even care.  Another site may be selling electronics among other items, but cannot ship the electronics overseas.  This may be due to voltage or warranty issues.  We are now also dealing with tighter rules regarding items for children.  CA for example passed a law prohibiting the sale of items that pose a possible choking hazard even it the item may not be made for children.  An example would be party necklaces.  See this site for an example: http://www.beadsbythedozen.com/pc-728-166-blinky-beadsbrblack-gold-beer-mugs.aspx
It would be nice to implement a feature where you can restrict delivery to on a product basis.
Katharina