I have experience as a tax payer in Estonia (employee only) and Australia (employee and business owner). In Estonia I login to my bank with my citizens ID card, click through a few screens ... and my tax return is done. All the financial information supplied by my employer to the government is immediately visible and checkable, not to mention donations made to tax-deductable organisations is also immediately visible. It is incredibly quick and convenient. In Australia it's just easier to leave everything to my accountant as they already have my quarterly business returns information; cost is still pretty reasonable (500AUD or so for the yearly business returns and the personal returns for my wife and I). But ... yeah ... in Estonia it just rocks. The ID-card based functionality for banking, digital signatures, tax ... just awesome.