This gist lets you keep IPython notebooks in git repositories. It tells git to ignore prompt numbers and program outputs when checking that a file has changed.
To use the script, follow the instructions given in the script's docstring.
For further details, read this blogpost.
The procedure outlined here is inspired by this answer on Stack Overflow.
People interested in making Jupyter notebooks play nice with git / GitHub might like to checkout ReviewNB. It's a code review tool for Jupyter notebooks on GitHub.
Disclaimer: I built ReviewNB.