Bob points out that there are some simple ways to check this out. The first one, is, please, USE YOUR EYEBALLS.
Case in point:
"Awhile back some clown sent me a bunch of political cartoons critical of Barack Obama and other Democrats that was headlined, 'AUSTRALIAN CARTOONS NOT SEEN IN AMERICA.'
"It ended with: 'These cartoons are not of USA origin. Thanks, Australia. Pass them on. The liberal American press will not.'
"If you looked closely at the credit lines on the cartoons, you'd see one of them was published by The Times Picayune, the biggest newspaper in New Orleans. Another was from the North County Times, a daily near San Diego. Two others were drawn by an American whose syndicated work — featured in the Washington Post, the L.A. Times and the Chicago Sun-Times — was nominated for the Editorial Cartoon Award in 2007 by the National Cartoonist[s] Society — our National Cartoonist[s] Society.
"If those cartoons were published in Australia, somebody in Australia was legally obligated to send money to the United States for the right to do so.
"There are plenty of good reasons to dislike the 'mainstream press' without dreaming up total fabrications that ruin your credibility."
Related: Rob Tornoe: Chain-Letter’s Claim of Australian Conservative Cartoons False
Related: Daily Politics has all of the cartoons here, as do a lot of other blogs. Most of the commenters quickly recognize the names of the US papers and US cartoonists.