In a valiant effort to nerdify this place even more than it may already be, let's talk spreadsheets! No, I'm not talking about some strange thing you do on your bed. I'm talking about things like OpenOffice/LibreOffice Calc, Microsoft Excel, or (maybe in 1992) Lotus 1-2-3.
Personally, I find that spreadsheets are an integral part of my life, and it'd be difficult to do without them. Even as I speak right now, I have six of them open, and that's probably lower than usual because I recently restarted LibreOffice Calc.
Most of mine are actually simple. I rarely need to do anything complicated with formulas, but I certainly do when whatever I'm doing calls for it.
Here's a sampling of some of the things I keep track of or calculate with my spreadsheets: Numerous personal financial things, cleaning schedules, TV series and movies, my weight (I've weighed myself almost every day for over four years), various trackers when playing games (like who has mastered each esper in FF6), automotive repairs and parts, my tire tread depth history, and a whole bunch of other things I have archived but am not using at the moment.
So, does anyone else completely go overboard in their use of spreadsheets?