Adding to Dan's note, here is today's story from Tax Notes International (no link):
The Bulgarian parliament passed a new flat tax on income on November 16, making Bulgaria the seventh EU member state to adopt a flat tax regime . . .
The new flat tax will replace Bulgaria's progressive, three-bracket income tax, with a flat 10 percent tax on income starting in 2008. Bulgaria had already slashed the corporate tax from 15 percent to 10 percent in 2006 . . .
Bulgaria is the latest in a number of Central and Eastern European countries that have replaced progressive systems with flat tax regimes. The flat tax revolution was pioneered by Estonia in 1994, and since then about 20 countries in Central and Eastern Europe have followed suit.
In this country, many pundits and presidential candidates would reverse President Bush's modest reduction in the top income tax rate from 40% to 35%. Those rates are more than three times higher than the new flat tax rate in Bulgaria, a former communist country.