Hoople - 2:40 am on May 10, 2011 (gmt 0)
Wow, tough crowd! Is this the Foo forum?
That aside the non-profit org that I do a few seasonal websites for has 6 in person events on those seasons. They use Twitter to alert followers to attendance filling up. Prevents a car full of anxious kids from driving 5-30 miles to an 'all full' event.
A second use that same non-profit group is to alert people to their general (open to the public) membership meetings. Many more followers than signed up members.
Many people I know have Twitter apps on their smartphones to interact with the niches they are interested in. My wife likes to 'reach out and touch' celebrities with thoughtful response Tweets and occasionally gets a Tweet back too.