bund-cake
A JavaScript bundler and minifier for express.
The JavaScript outputs to /assets/bundle/[bundled-file].js
Usage
In app.js (after your app.configure() block)
GLOBAL.bund = require('bund-cake')(app)
And this snippet of EJS in your view,
<%- bund.js('./public/javascripts/annoying-popups.js', './public/javascripts/one-weird-tip.js') %>
Issues/Concerns
I haven't tested this with JS files from another domain or CDN. The very first hit to the server is slow, but is okay after that.