The correlation is strong with this one (r = 0.74)! The IQ data comes from a study conducted on 34 countries, between 2002 and 2006, by professors Richard Lynn and Tatu Vanhanen. The study has been criticized for its small sample sizes. Lynn and Vanhanen extended their results beyond the original 34 countries to neighboring countries.
Data source: Here is a link for Average IQ by country. They get their data from a study conducted by Richard Lynn and Tatu Vanhanen. I got the average internet connection speeds from this Wikipedia article. The connection speed data was the smallest of the two data sets. The merged data sets are located on my github page.
Tools: I used python and D3plus for the visualization.