The cool website analyzewords.com uses text mining to analyze personality traits based on tweets. You enter a Twitter handle and within seconds get a nice graphic analysis of the tweeter in terms of Emotional Style (upbeat, worried, angry, etc.), Social Style (arrogance, personable, etc.), and Thinking Style (analytical, sensory, in-the-moment)
James W. Pennebaker, a cognitive psychologist, who is an expert in psychological trauma research. The underlying engine uses text mining -- it counts words of various types (such as "angry" words), and uses the counts to get a picture of the writer. To learn more, see Pennebaker's new book.
My guess is that the results are culturally-dependent in the sense that they reflect North American language use. However, it might just give an interesting glimpse into Bhutanese tweeters' personalities as well!