The App.net guys launched their Broadcast system a short while ago (http://blog.app.net/2013/11/21/announcing-app-net-broadcast/). It's basically a tool for subscribing to push notifications - a mix of Twitter and RSS feeds, if you will.
It is really hard to find people who are using this in interesting ways beyond mere RSS aggregation, so I was wondering if anyone had some good broadcasts to recommend.
So far, I am only subscribed to Pro Publica: https://app.net/c/2wtz.
YC also have a bunch of them: http://blog.ycombinator.com/subscribe-to-y-combinators-broadcasts-via-app-dot-net.