Two of planet Earth's wealthiest men – Microsoft co-founder Bill Gates and New York City Mayor Michael Bloomberg – are teaming up, through their foundations, to spend $500 million on a worldwide campaign against smoking. The New York Times reports the campaign, which will work with other groups including the World Health Organization, will urge governments to raise taxes on tobacco, ban smoking in public places and advertising to children, and offer people help in kicking the habit.

Only about five percent of the countries in the world have antismoking measures of this sort, but polls show the war on tobacco has really paid off in the U.S., where the percentage of population identified as smokers has dropped from 41 percent in 1944 to 21 percent in 2007. That's according to Gallup surveys which also show big differences in smoking rates around the world. The top five were Cuba, at 40 percent, followed by Kuwait, Chile, Russia and Belarus (all at 37 percent); the bottom five were Nigeria, at 6 percent, followed by El Salvador and Ghana (both 8 percent), and Afghanistan and Ethiopia (both 9 percent).

Anti-smoking measures – which are said to be having some initial success in China - have gradually won wide support in the U.S. but have also sparked strong emotions. Gallup polls show a rise in the number of smokers who feel unjustly discriminated against as a result of smoking restrictions. About a third of smokers felt that way in 2001; forty-seven percent said the same last year. During that same time period, support for restrictions on smoking dropped among smokers, from 65 percent to 51 percent, while among Americans overall, the percentage who said smoking in all public places should be made "totally illegal" stayed about the same, at or near 40 percent.