Firefox , the browser which is increasingly finding its acceptance , has a Pubsub icon
in it ..
Whats Pubsub ?

PubSub is a matching service that instantly notifies you when new content is created that matches your subscription. Using a proprietary Matching Engine, PubSub is able to read millions of data sources on your behalf and notify you instantly whenever a match is made
http://pubsub.com

online experience is becoming more pleasant