Could a cryptocurrency impose directly in its own block-chain geographic identifiers? Since they are mined on computers they would have a locale 'flag' enabled this could then be updated at each transmission to a new wallet (it would be necessary to build a wallet able to read habitual and actual location of user.
This would have the advantage that each transaction would automatically know the originating country of the payment (allowing for VAT/GST/Sales Tax to be applied) whist still allowing the purchaser to be anonymous.
Furthermore the Ethereum block chain would allow for smart contracts which could perform the VAT calculations and payments directly., since it would know where it last originated from. Of course to be useful the block chain would have to be able to 'read' or be piped the current rates. It would also be interesting to see how this project would show geographic distribution of the block-chain. Of course this would be most useful if tied to a physical commodity or fiat currency, How can we use the blockchain to validate holdings?