modularity is deathpic.twitter.com/82z52vJBsg
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
@vgr in the sense of separate groupings? Alexander thinks boundaries are non-segmentary (at least US) http://www.rudi.net/books/201 (& that's good)
@vgr (this is the first part of that, might be up your alley http://www.rudi.net/books/200 )
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.