I have a project which is heavily JavaScript based (e.g. node.js, backbone.js, etc.). I'm using hashbang urls like /#!/about and have read the google ajax crawlable spec. I've done a wee bit of headless UI testing with zombie and can easily conceive of how this could be done by setting a slight delay and returning static content back to the google bot. But I don't really want to implement this from scratch and was hoping there was a pre-existing library that fits in with my stack. Know of one?

EDIT: At time of writing I don't think this exists. However, rendering using backbone (or similar) on server and client is a plausible approach (even if not a direct answer). So I'm going to mark that as answer although there may be better solutions in the future.

There is one implementation using node.js and Backbone.js on the server and browser https://github.com/Morriz/backbone-everywhere