There is no setup needed to use the Arduino Wire library, as it comes installed in the Arduino IDE. You can find the library files by navigating to Arduino/Libraries/Wire, but it's not recommended ...

We’re still not sure exactly how [connornishijima]’s motion detector works, though many readers offered plausible explanations in the comments the last time we covered it. It works well… ...

Well tech tinkerer Joe Desbonnet has whipped up what he dubs "poor man's NFC" using an Arduino, some magnet wire, and any compass-equipped Android smartphone (which is almost all of them).