Google's semi-secret WiFi network has established a foothold in New York City.  Someone who recently visited saw a plaque (left) and took a photograph. As most people know, Google dipped a toe in the WiFi market in April by sponsoring a  free hotspot in San Francisco's Union Square. So how long is it going to take before Google unveils its WiFi plans? I mean, you can't have Om Malik and IP Media Monitor do all of Google's PR work, right? For some good insight into Google's Secure Access service, check out AugustJackson. Robert Scoble thinks Google's WiFi plans may be focused on building a better search engine. The idea is that Google will have another way track Web traffic.