vilmoskörte's [answer](http://apple.stackexchange.com/a/60181/10167) appears to be a good one, but I took it upon myself to make a tool that does this for my own education. I put it on GitHub.

### [WhereAmI](https://github.com/robmathers/WhereAmI)
A simple command line tool. No options, just runs and outputs Lat/Long, accuracy in meters, and a timestamp. It will need OS X Location Services to be turned on (System Preferences > Security & Privacy), and permission to gather your location (OS X will prompt you on first run).

[Direct Download Link (.zip)](https://github.com/robmathers/WhereAmI/releases/download/v1.02/whereami-1.02.zip)