In case you missed them, here are some articles from December of particular interest to R users. The blog is.R ran an excellent series of R tips and applications in December, with posts including working with Stata files, working with graphs and networks, and text analysis. Kohske Takahashi provides R scripts to create a collection of optical illusions. Highlights of the latest issue of the R Journal. Coursera has a new free online course on data analysis with R starting on January 22. A video tutorial on using the sqldf package to manipulate data frames using SQL. Esteban Moro Egido visualizes the growth of political revolutions using Twitter and R. Videos from Coursera's introductory course on R are available on YouTube. The Revolutions blog celebrates its 4th anniversary with the top 10 posts of 2012. An analysis using R suggests the UK's NHS could save hundreds of millions on prescription drug costs. "Try R" is a new on-line interactive tutorial for R. RStudio's "shiny" package for interactive web-based R applications is now available on CRAN. Revolution R Enterprise 6.1 adds the capability for fitting rpart-style tree models to data in Hadoop HDFS. A New York Times graphic editor shares how he uses R base graphics to create bar charts in the newspaper. Some non-R stories in the past month included: how to make a 360-degree photo of a landmark, influential data scientists on Twitter, fire and magnetism, and a card trick using base 3 arithmetic. As always, thanks for the comments and please send any suggestions to me at david@revolutionanalytics.com . Don't forget you can follow the blog using an RSS reader like Google Reader, or by following me on Twitter (I'm @revodavid). You can find roundups of previous months here.