Lahore vs. Bangalore vs. San Francisco on Twitter

Twitter added a search feature recently. In the spirit of micro-blogging, here are a few quick and interesting twitter search results:

Lahore: 15 results, Karachi: 35 results, San Francisco: 2038 results, Bangalore: 194 results

Translated into Twitterers (or Tweeters or whatever) per 1000 citizens (using Wikipedia), its:

Lahore AND Karachi (both have approximately the same ratio):  1 out of 0.57 MILLION tweeters, San Francisco: 1 out of 396 tweeters, Bangalore: 1 out of 27216 tweeters.