Definitely - playing with any data is the best way to learn the tools. Just for giggles I built a tool that extracts all oracle permissions, sums that up into

Definitely - playing with any data is the best way to learn the tools. Just for giggles I built a tool that extracts all oracle permissions, sums that up into relationship information using PIG (this schema owner reads from here, writes to there, etc) and used first R/ggplot2 and then later Gephi to plot the results. None of the data sets could be called big data by any stretch, and I could have done the processing more quickly with perl or python, or even a mix of shell commands. But that wasn't the point. It was to expand on the one day of training I'd had and help cement the ideas, and frankly it was to have fun. Find something that you're passionate about or just plain sounds like fun and then use the tool you want to learn to solve your problem.