UGC + Wi-Fi = WeFi
WeFi is a startup with software that locates and maps open Wi-Fi hotspots. Nothing special about that — there's lot of services that help you find Wi-Fi. What WeFi does that's a little different is to add a social networking component, with which users can easily submit hotspots they find for sharing with other WeFi users. WeFi seems to hitting all the Web 2.0 buttons: social networking, Twitter integration, and a "beta" tag built into its logo. Unfortunately, no Mac software is available (they recommend BootCamp!).
