Here’s an idea for an activity we could add to R Club: http://cacm.acm.org/magazines/2014/9/177929-refining-students-coding-and-reviewing-skills/fulltext
The author writes about it with more traditional programming examples rather than data analysis stuff per se, but I think it would work really well for R Club. A lot of the learning curve for R is the programming-y stuff (getting used to using variables, functions, arguments, etc.), and I think code reviews would be a great way to learn that stuff from each other, in the same way that the author describes in his post. I also think code reviews would be especially, specifically awesome for stats and R because of the super redundant nature of both – there’s always more than one way to skin a cat, as the disturbing proverb goes, and it’s great to learn a variety of tools and approaches for statistical analysis in general, and stats in R in particular. Code review would certainly facilitate learning alternate ways of doing things from each other.