In honor of its 250th anniversary on September 24, Guinness is helping fans find the beer with a Guinness finder iPhone app. As a celebration of the company, and helpful for getting sales, the app was covered by several media outlets, including NBC New York:
The app works with the phone's GPS to point you right at the closest creamy stout, drawing you a map, as it were. And that's not all it does. The Guinness finder also has a tutorial in pouring the perfect pint and a ruler to measure the head -- functions sure to annoy all but the most tolerant of barkeeps.

I personally prefer my Guinness with a side of Dublin… but there it's not a challenge to find Guinness at all.