I have been playing around with a software called Easy WiFi Radar on my notebook for quite some time which is probably the easiest way to find and use open wireless connections. The main advantage of the tool is its simplicity. All that needs to be done on the part of the user is to click the button of the application to start it.
It displays a radar like image with different colors dots. Green dots mark free wireless connections while red and yellow ones mark inaccessible ones. Once a green spot has been discovered by the software it automatically tries to connect to that Wireless access point to access the Internet.
It’s opening the default browser and loading a test website. A message stating the success will be shown if the connection was successful. It is really amazing how easy it is to find open wireless access points in towns. Should be harder if you are living in a rural area though.
I would not advise to check the mail from such a spot though unless encryption is being used. It’s not likely but possible that someone is using the open access point to snoop on the data of everyone who is connecting to it. Easy WiFi radar is available for Windows and Pocket PCs.