said by mrbueno 
:It's that simple.
WiFi outdoors can work, but you have to know what you are doing and you have to have some clue to do an install. Most of these installs try to ignore the fact that 2.4Ghz doesn't like wood, water, concrete, or metal. 2.4Ghz wants it's space.
Those of you wanting a working WiFi experience in one of these cities should buy an outdoor unit and get it above the trees. That will help alot. Then all you have to worry about is the interference created by hundreds of APs seeing each other on the same channel, the fact that 802.11b/g isn't meant for outdoor use, and the nearest AP having too many associations.
There is nothing like being in a NYC park in a hip upscale urban area in Manhatten with very tall buildings on all sides. And when I try to get the park's wifi, I get over 400 SSID. Plenty of open APs. 
