You can build a reputation as an expert spreadsheet developer. This certainly doesn't hurt the resume. Using Excelville.com to sell spreadsheets allows you to set up a profile with your work, biography, and other info that certainly makes for good conversation material during interviews.
In today's competitive climate, proper business management and organization plans are crucial for companies that strive to maintain leading positions on the market. Apart from a substantial capital, company owners have to invest lots of time and effort in order to maximize the efficiency, profitability and exposure of their business.
You may also want to track your current spending on one sheet with columns for different categories. Some individuals will list the budgeted amount in one column and then list the actual amount spent in the column next to it.
You could make money doing something you love (or like [or maybe not so much but just really good at]). It's great to see a spreadsheet come together, and usually a lot better than what you originally envisioned. Especially when the dang thing works.
what is a spreadsheet used for
uses of spreadsheet