Danny, if there is a way for the fee to be added, via the technology, so that when I send the BTC I cannot choose to not add the fee, then I will be happy to stand corrected.  I know that with blockchain.info I can choose not to add it.  It is entirely up to me, and if I say no, then it doesn't happen.  The person receiving the BTC has no say in it.  Maybe I am wrong, but I don't think that I am.  They can choose to not give me what I paid for until confirmation, but that is all.

Also, with Blockchain.info unconfirmed transactions get cancelled after 24 hours.

Thus, if I were to use that wallet to buy something at a store I could not pay the fee and I *might* get a free lunch. 

Zero confirmations is definitely not instant under these circumstances.  Zero confirmations simply means that the transaction may go through, and with no miner's fee paid there is a good chance it won't.