Good methods for creating high quality scatterplots What free programs/software are best for creating publication-quality scatterplots? 

I'm looking for something like this: 



Square, small (take ups about 1/4 to 1/3 of a single column in a two-column paper) but high resolution. Preferably with ability to add axis title and trendline. 
Thanks
I'm not sure this question fits well here on academia.SE, but if you want free, beautiful, and powerful, it'll be hard to beat R. See e.g.

http://www.slideshare.net/dataspora/a-survey-of-r-graphics

http://www.sthda.com/english/wiki/ggplot2-scatter-plots-quick-start-guide-r-software-and-data-visualization