I teach ideology, and most textbooks in comparative politics include some version of the graphs above.
That said, for various reasons I worry less about the extreme right wing in American politics. As I noted previously, "it's my personal belief that radical left-wing ideology is the greatest threat to the country today."
That said, we'd probably have less confusion over who's on the left or the right if folks better understood the various ways to graph the ideological continuum. James makes a good point below, although he needs to clarify this point about "racism is neither right-wing nor left-wing ..." Textbook definitions of Nazi ideology distinguish it from fascism with respect to theories of racial millenarianism. That said, it's true that anti-Semitic ideology today is found on both the extreme left and extreme right:
I prefer to think of ideology as a circle, rather than a line. Left and Right have meaning but, as one gets to the extremes on either side — depicted as anarchism in the top chart and “Everyone Against Everyone” in the second — the views diverge.
I actually prefer the bottom figure best in that it groups authoritarian states — Communism, Theocracy, and Fascism — very tightly and depicts, for example, Socialism and Libertarianism are near opposites. Additionally, it contrasts all governmental/ideological forms with Anarchy, or the absence of government. Those who murder to carry out their political agenda are in that category; their particular ideas otherwise don’t much matter.
Finally, I should note that racism is neither right-wing nor left-wing (nor, for that matter, is it centrist or anarchist). It exists at all points on the spectrum and isn’t a political ideology at all. Von Brunn’s hatred of Jews isn’t what makes him a right-winger but rather his views on politics.