Image via CrunchBaseWeb 3.0 is approaching and everybody is running towards that goal.
Twitter is leading race and it gave its API to developers so they can make something monetizable. Google use Hosebird API, so it can change its search result page and include real-time results. Facebook changes its front page so it can join race.
Mozilla is also player who waits its change in background and you can follow real-time number of downloads of Firefox instances.