Inspired by the buzz around Breakup Notifier, last week's "Defriend Day" (http://www.huffingtonpost.com/2011/03/04/defriend-day-etique...), and a good excuse to give Node.js a spin, I just launched a new Facebook app: Defriend Alert. The app sends you an email whenever someone defriends you on Facebook.
I built it over a two day span with Node.js, Express, and MongoDB. It's hosted by Duostack (which is an awesome service, btw). I'm typically a Rails guy, and this was my first Node.js app. Very impressed. Looking forward to cranking out a few more apps over the next few weeks.
Let me know what you think!