There are a number of ways of delivering data in real-time but until recently it has looked like PubSubHubbub, with the backing of Google, was going to be the preferred method. However, the past couple of weeks have seen a couple of interesting developments which could indicate that the developer community may actually prefer HTTP Streaming.
Topsy, a search tool based on real-time social media activity, has unveiled a new service called Topsy Social Analytics that tracks the rise and fall in popularity of specific pieces of online content as well as broader trends in online discussion. The analytics tool, like the Topsy API, uses publicly available data from Twitter to rank content and identify trends.
As Facebook is one of the major players and MessageMe is a new kid on the block, you would expect that the latter would be intimidated, if not crushed, by any direct attack from the social giant. In this case, it doesn't seem to be so. Despite Facebook recently cutting off MessageMe's access to the Facebook Friend Graph, the newcomer has since grown in popularity and managed to raise $1.9 million.