The wildly popular Twitter has become an important tool for net surfers to share information. With its popularity, however, come new, important issues such as: a). how to cite 'tweets', and b). how to properly archive the tweets that are valuable to you and keep your ahead above the information 'deluge'.
If you have these or similar questions hanging in your head, you may find this post useful: http://gunther-eysenbach.blogspot.com/2009/04/how-to-cite-twitter-how-to-cite-tweets.html
By the way, if you are twittering already, you may want to include the East Asian Library into your network :)
In addition, APA also has information on Tweets citations. Please visit the relevant web page.