The more I use R, the more impressed I am with it as a tool to explore, document and share your work.
GGPLOT is perhaps the most user-friendly plotting tool out there, while still being suitably flexible and expressive. The addition of GGPLOT to Python is a great step forwards for Python users.
R Markdown is a sensational tool for documenting your work, sharing your research process with others and reproducing regular workflows. I am looking forward to getting familiar with IPython notebooks too. On the same theme, try out Slidify or RPresenter for producing integrated HTML5 presentations.