JiWire released a free Firefox toolbar that promotes their SpotLock VPN service, but also provides a large variety of useful information, including network status and signal strength as well as the security of Web sites (it notes when SSL is active for a given page). It"s a hotspot finder using JiWire"s directory, and the "i" (info) button shows you a large amount of information about your adapter and the access point to which you"re connected.
The toolbar is for Windows Firefox only for now, but JiWire promises versions for Mac Firefox and Safari and Windows IE.