I just got back from my local Starbucks in Foster City, CA where I was doing a little investigating of my own after reading on Ars Technica that AT&T quietly rolled out free Wi-Fi access for the iPhone at some hotspots. It appears the rumors are true. After firing up the Safari browser on my iPhone, I was taken to an AT&T page that clearly said “Free AT&T Wi-Fi for iPhone.” The page …