Hacking maps.

This doesn't really have anything to do with dads or parenting or kids or whatever, but my new favorite thing on the Internet is Google Maps. Typically of Google, it's simple, easy to use, and incredibly powerful. You can find just about any location instantly, get directions, and even see a satellite image of what you were looking for. But the coolest thing is, Google has opened up all the data (via XML) so people can make all kinds of cool stuff with it.