If you can’t get a signal in Manhattan, blame AT&T. They’ve pretty much admitted that their network in New York is completely inadequate, and now, three years in, they’re taking some concrete steps to alleviate the problem — for tourists, at least.
The biggest concentration of AT&T users in New York probably is in Times Square; think of all those people on the shared voice/data network, emailing pictures to their nieces, checking the map to make sure they’re in Times Square, and all that. AT&T is going to give all these fanny-pack-wearing pretzel junkies (well, the ones with AT&T phones) free wi-fi access for their phones.
They’re hoping that by offloading some high-traffic areas onto wi-fi, they might unload some of the burden that’s been breaking the backs of iPhone users for the last few years. I’m not sure that it’s really going to make a dent, but hey, it’s something. If it makes a difference, they’ll probably roll it out in other major metropolitan areas, so stay tuned.