SCARYspicemonster your second link re "In fact, the marginal top rate in most countries rises substantially when considering the all-in rate of taxes on income, to 61% in France and Turkey, 62% in Denmark and Sweden, 65% in Japan and 66% in Belgium. The highest all-in rates for taxpayers in the United States fall in the 40?48% range, depending on the State where they are resident."
refers to 1998 and things have changed a lot since then.
The 39.6% rate referred to there is now 35% (and only applies above $373k - on the £40k on which you'd pay 40% tax in the UK, you'd pay 25%), and I think a better picture of taxation is tax as a percentage of GDP, as there are many ways for the government to tax people, not all of which are income tax.
I haven't seen many people claiming taxes are lower in Europe - Tracey Emin perhaps did, but she is clearly an idiot anyway.
Our tax take is slightly below average European levels (but above Spain, Portugal, Ireland, Greece), but it is significantly higher than pretty much every Westernised non-European countries - Canada, Australia, New Zealand, Australia, USA, Japan, Korea all have sharply lower tax burdens.