I presented a paper,  "Twanguages: a language census of Twitter", to the 33rd Internationalization and Unicode Conference on October 16, 2009.  This page has links to my paper and my handouts.

This was my abstract, from the Unicode conference program for my talk:

What "twanguage" do you "tweet"?  Twitter, the buzzing conversation of brief web and SMS messsages, exploded into wide use in 2009. But just how wide?  To how many countries has it spread?  And into which languages?  We aimed to find out. Our "Twanguages" project is a language census on a sample of Twitter's global traffic. Come hear our findings. Which are the top languages? Are #hashtags localised? How does language correlate with location?  And which Unicode character is the most rarely used? Accessible to everyone, this talk is especially interesting to students of social media and of quantative language analysis.

'Twanguages: a language census of Twitter' paper by Jim DeLaHunt is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.
Based on a work at jdlh.com.