Stanford's Data Wrangler for visual data exploration

On several quick projects and tasks, Wrangler has saved me days of brute manipulation, and helped me explore new methods faster.  It's a fantastic tool for getting your data into the format you need it, so you can start doing more interesting things with it:

I've found particularly handy its ability to fold and unfold fields in various ways, and its visual previews of manipulations as you go.  But best is its output of a python script, so that once you've visually manipulated your data as you need, you can quickly and automatically repeat it.  Since R still has a way to go for ease of data manipulation, but is top-notch in data analysis, combining these two is fantastic for getting things done.  

Excel-oriented people will also find it very user-friendly and powerful.

Here's their introductory video

Overall, this tool is a great example of how approaching data visually helps you do more effective analysis.  The Wrangler team has done a great job putting this together.