This may be in the notebook or on Seaborn's homepage (http://stanford.edu/~mwaskom/software/seaborn/), but someone compared seaborn to pandas in that it provides a terse API to a great base package (matplotlib and numpy, respectively). I'm looking forward to using this more.
Pandas is amazing and I use it all the time, but the API for things like hierarchical multi level indexing is very complex (it has to be - it's a very difficult thing).
I find it nicer than bare-bone matplotlib for plotting (one line of code per standard plot + very pleasant graphically).
I knew that it exists for some time (and I had it already installed) but only today I rediscovered it as a really useful tool for default plots in my data analysis / data exploration.
There was one about detecting bubbles in liquid for the purposes of reducing spilling that was very interesting
http://nbviewer.ipython.org/github/soft-matter/trackpy-examp...