Also, some of the btc I spent came from Satoshidice, which is a game of chance. Dutch law dictates you have to pay (income-) taxes over the net amount gained (wins minus losses) to retrace this (as a third party) is a next to impossible task. (to prove)
As long as you dont convert BTC to local currency, you cant pay taxes. Bitcoin is not foreign currency, it is the same as WOW gold.