Politwoops and other Twitter-related sites

Politwoops: (deleted tweets from politicians) enables keyword searching for deleted tweets. It is offered in a number of countries.  Each entry gives the amount of time before tweet was deleted. Sometimes the cause is a spelling mistake but in other cases to remove errors or other changes.
See UK MPs deleted tweets: http://www.politwoops.co.uk/ 
and the US site: http://politwoops.sunlightfoundation.com/users 

Also on the twitter theme:  New user Warren Buffett
According to the BBC he acquired 140,000 followers in 3 hours.

Tweetminister is a good directory of MPs using twitter it also has news stories about current trends.
Other key economists using twitter include

• Paul Krugman – New York Times.
• Freakonomics
• Wall Street Journal 
• Economy watch has another 20 top recommendations in this slideshow