These are some things I've done in my spare time.
Visualization using Plotly.js to compare running race times
Data gathering and analysis to demonstrate how unreliable my bus home is.
Data analysis in Python with pandas, and visualization in d3.js.
My notes and enhancements of a the "Deep MMIST for Experts" Tensorflow Tutorial.
I made the network considerably smaller to train on a laptop.
Data analysis in Python with pandas, graph using matplotlib, and then an attempt at prediction using sklearn. The visualization script was featured in a Kaggle newsletter.
Word counting in Python/Spark, using my Masters and Honours theses, with visualization in d3.js.