Decided to reissue this as a poll.
"R", pronounced 'AAARRR', is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS. R is similar to Matlab, Mathmatica, SAS, SciLab, etc. with a huge open community support system. I call it a different kind of IDE (Information Development Environment). It is one of the favorite tools in a Data Scientist's tool chest.
Personally, I have recently been using R to demonstrate many of my Big Data projects wherever I can. Mostly for the graphic and visualization capabilities after the data manipulating stage. And while I haven't even come close experimenting with all of the available plug-in packages for R, I'm trying to get more and more familiar with all of R.
One way I do this is by subscribing to the R-bloggers mail list which is a daily newsletter of collected R related topics and blogs, but mostly cool working code samples and use cases. This newsletter can be found here at R-bloggers | R news & tutorials from the web. My most recent favorite piece is "Arteries of the World" describing the plotting of billions of geo-tagged tweets in about 20 lines of R code. It can be read here The arteries of the world, in Tweets. The pictures are awesome!
Checkout R and get started looking at Big Data from a Data Scientist's point of view.