The United States has one of the best approaches as how to treat Bitcoin from a tax perspective. The government simply views the coins as property and you pay a capital gains tax (unless you live in Puerto Rico) when you sell them. You can still get jail time if you sell them in bulk as an unregulated money exchanger but most people wouldn't fall into that category. 

More countries should take this simplistic view on how to tax/regulate Bitcoin and stop thinking of it as a currency.