I've been playing with JS a bit recently, and have released a client-side library for extracting postal addresses and geocoords from webpages - it's intended for use in bookmarklets and browser extensions:

http://zipripjs.com/

I've also made it work with node.js - which means it's installable via npm. For what it's worth, it's considerably easier to create a new user account for node packages (no human intervention step), and there's a built-in publish tool...