I've read a few examples of automated deployment of node.js/express applications using Git pushes and hooks.
For example, as documented here: http://catchvar.com/nodejs-server-and-web-sockets-on-amazon-ec2-w
This looks like a good idea, but unfortunately I'm using Mercurial.
Can anyone point me in the right direction for achieving the same thing using mercurial? (and SSH)
Mercurial doesn't support separating working directory from repository directly, but for your purpose you can use something like hg archive files ~/www in a changegroup hook.
I think this question has a solution which may be close to what you are looking for even if a little tricky. Otherwise i would appreciate knowing how you solved the issue if you were able to?