If you want the option of reversing transactions then you better just stick with PayPal or any other of the dozens of Fiat currency payment services. I agree fully with the above posters that irreversible transactions are one of the best features of Bitcoin. Of course you have to be attentive and diligent when sending coins and copy/pasting or typing addresses out, knowing that our BTC transactions are permanent. To enable transactions to be reversed would seemingly require a central authority and the trusting of that authority. And decentralization is the way forward, not stricter controls and government oversight.