I've just setup node inspector for debugging. I created basic a test app based on the documentation on nodejitsu.com. I've written an overview here too.
Install node inspector globally:
npm install node-inspector -g
Run your app in debug mode using the --debug flag:
node --debug index.js
Run the inspector in a new terminal specifying the port of your app:
node-inspector --web-port=8080
The port is whatever port you are running your app on, the example above is 8080.
Visit the debugger app by visiting http://127.0.0.1:8080/
Voila.