Located in London, I measured the RTT or round trip time to 574,691 random webservers and plotted the times on the globe.
Discovery was done with masscan, measurements using hping and plotting with an old Python script I've revived and enhanced.
This is part of the next writeup on my blog, with which I will be posting any of the code I've used.
Just a little nitpick: could I persuade you to consider a color scale that goes from light to dark luminance like viridis? https://cran.r-project.org/web/packages/viridis/vignettes/intro-to-viridis.html
Looks great I'll be checking different color scales, I'm still figuring out the plotting library though.