Here is a list of useful Wi-Fi hot-spot directories:

http://www.wi-fihotspotlist.com/
http://www.wi-fizone.org/zoneLocator.asp?TID=7
http://www.nodedb.com/
http://www.jiwire.com/
http://www.hotspothaven.com/
http://www.geektools.com/geektels/

You forgot http://www.wififreenet.com/ :)

And I might add, that people may be interested in following the travels of Wifi-Guy (http://www.wifi-guy.com), who is out on a self-less (PR) mission to stay digitally connected across the great USofA.

For the last few weeks, the WiFiGuy has been on the road discovering and reviewing the most unusual hotsposts across the whole country and documenting his travels in a blog. So far he has been up the West Coast through West Texas, New Mexico, Nevada, California, and Oregon. If you know of a really unusual hotspot in your town, be sure to contact the WiFi-Guy.

He's gonna be heading up to the Windy City soon, then cruising to the East Coast. If you run into him, he'll give you some cool prizes.