Yahoo’s buzz search index is cool. As a way to discern what is happening in the ‘real’ world and what the ‘buzz’ is search terms are a vital source. You can discern events and communications that resonated with people not only on the web but on TV and through other media. For example TV execs searching for ‘life beyond the broadcast’ would do well to look at search terms as a concept to hook things around and play with.
Ways of displaying search queries and displaying them back to the user could also be a good way of capturing the ‘mood’ or momentary ‘zeitgeist’ of a population.. like this graphical represenation of news items but for key buzz searches. Being clever with user stats and displaying them in a transparent yet interesting way to the user is going to be key for web services going forward, i’m sure of it.