I think what distinguishes a true slopegraph from a parallel coordinate plot is that in the former y-axis remains the same variable and scale. On the other hand, many of the "almost" examples from that link are really parallel coordinate plots.

I agree. I've appreciated them (lineplots, slope graphs, or "bumps charts") since Kaiser Fung redrew an Economist chart of birth ratios in Indian states:

I think what distinguishes a true slopegraph from a parallel coordinate plot is that in the former y-axis remains the same variable and scale. On the other hand, many of the "almost" examples from that link are really parallel coordinate plots.

I agree. I've appreciated them (lineplots, slope graphs, or "bumps charts") since Kaiser Fung redrew an Economist chart of birth ratios in Indian states:

http://junkcharts.typepad.com/junk_charts/2011/04…

Here's a resource for creating them in Excel:

http://www.databison.com/index.php/bump-chart/

Ben Fry’s Baseball Chart looks more like an art-museum-security-laser plot. Or, maybe that's the 'no association' condition.