Boorstin's book is fantastic, and well worth reading. A good example of pseudo events are most of the Word of the Year lists, which are, for the most part, manufactured by sellers of dictionaries in an attempt to get free publicity. That's the context I was thinking of in the most recent Errata post.
I had a quick look but didn't really find an example. Would a pseudo event be something like the (modern) Super Bowl where you have weeks of hype before the game, the game itself (relatively short), another week of analysis and froth, a whole industry of Super Bowl marketing and souvenirs and whatnot, and the whole shebang actually only loosely connected to the football itself?
"In The Image, Boorstin describes shifts in American culture - mainly due to advertising - where the reproduction or simulation of an event becomes more important or 'real' than the event itself. He goes on to coin the term pseudo-event which describes events or activities that serve little to no purpose other than to be reproduced through advertisements or other forms of publicity." - Wikipedia