I'm a big fan of data crunching, data analysis, effective communication and using a bit of psychology to tell a story.
My first introduction to spreadsheets was Excel 95 and I was hooked so I guess I'm a data crunching nerd. I was a casual user until I really needed to use it for data analysis ten years ago. The group I worked for was looking at product failures and trying to convince the engineering teams to change. It was easy...not! But that's when I discovered Pivot Tables and all those great look-up functions. I could plug in historical data, run it through Excel and make all these fancy charts. Then I actually got an engineering team to add a feature!
Of course it wasn't all data that convinced people to do things. The other side was communication; telling a good story and giving the WIIFM (What's in it for Me?). I've spent a lot of time putting together visual communications using PowerPoint so I guess you can say I'm well versed in that too. Powerpoint is a great tool to tell a story and can definitely influence without too much text (hint: high quality images).
Lastly I'm a fan of psychology, especially individual behavior and group dynamics. What makes people tick and how to influence for the greater good.