“The next time you check a street address on Yahoo, you should know that it took days and months of driving by people like Mark Chilianis and Bill Wong to make sure you plot the best possible route to that party or appointment,” writes today’s San Francisco Chronicle.

“Chilianis and Wong work for Navteq of Chicago, which collects the digital map data used by Internet companies and car manufacturers, many of which now install navigation systems in automobiles.

“At any given time, many of the company’s 575 field researchers are driving around the country gathering street names and taking note of turn rules, speed limits and other information.”