Area deCoder Firefox Extension converts North American telephone area codes to localities
Click on the telephone icon in the status bar to expand/minimize. In expanded mode, type the 3-digit area code in the smaller box, and press [Enter] to see its locality in the larger box.
Firefox 4+ Users: Area deCoder not showing up? Ctrl + / toggles the Add-on Bar display.
I wrote Area deCoder years ago over a weekend to meet a one-off need. I have been maintaining it pretty much as-is for anyone who still finds use for it. If you know of anyone who wants to fork development to include more data, use a different ff control mech, or even move it to a different platform, just pass them my way, and I'll give them everything I have. Until then, I've run out of time/motivation and will probably just keep updating the data and ff version. In any case, I'm glad that there are still people out there that find it handy. Above all, thanks for your support and kind words over the years!