I realize that scalability probably wasn't a concern when you made these demos.. but it doesn't look like any of these can handle many concurrent requests (incoming, or outgoing to facebook).

Are any of these frameworks even compatible with the event driven mechanisms like twisted, tornado, etc?

I'm having to pick up Python since a lot of the webapp infrastructure at the startup I joined is Python/Django and I haven't really liked it so far, especially since everything we do would benefit from being done in an event loop (tons of IO to background services that make web requests block)