Zeitgeist is a German word that translates to mean 'spirit of the times' and conveys a sense of mood of a period in time through collective public consciousness, particularly through cultural, intellectual, political, ethical, spiritual and sociological interests.
Unfortunately, the word is often misunderstood and used as a convenience in denoting media interests.
The Guardian recently launched their Zeitgeist as a visual record of what online readers currently find interesting on guardian.co.uk at the moment.
Not exactly a Zeitgeist, but a graphical representation of popular articles in the online edition of The Guardian. Why not just label it popular articles? Ironically, in introducing that new part of the website, The Guardian blogged with the headline 'What's hot? Introducing Zeitgeist' - so why not call it 'What's hot?'. Pretentious and a gross misuse of a wonderful word. The Guardian definitely does not understand the Zeitgeist.
Der Spiegel, being a German news magazine, understands what it means and has a separate Zeitgeist section in its online English language edition in which editors include a mix of articles. Of course, its German language edition doesn't need a separate Zeitgeist section because the Zeitgeist is evident in its various sections.
Google uses the word Zeitgeist at the end of every year to list the most popular search terms of that year as an indicator or list that reflected interests for that year. A better use of the term, but probably more appropriate to label those lists as an annual aggregated list of 'popular search terms'. However, they are an indicator of the Zeitgeist, but not the Zeitgeist.
Twitter lists the most popular topics of tweeting (comments in 140 characters or less) in real time under the heading 'Trending: Worldwide' (or various other locations). It should be possible for Twitter to aggregate this at the end of each year. Twitter's trending topics would be an even closer indicator of the Zeitgeist, but given the word limitations of the platform, would only be superficial.
The real people who understand the Zeitgeist are actually in a position to influence it. And of course, certain bloggers.