I am a business lawyer but did my undergraduate degree in political science, which makes me a bit of a faker among some of the business types I spend time with. However, the one thing that always gives me credibility is the way I can make a spreadsheet application dance. I've written in the past how, for certain problems, a spreadsheet application can double as a simple application development platform. Here is the Settlement "App" I've built in Numbers.
If you are looking at getting better at spreadsheets, Rob Griffiths wrote up a nice summary at Macworld of nine things you should know how to do with a spreadsheet.