Retweeting: 'Followers' look to 'leaders' as social networks grow - CNN.com
Tips for Retweeting
1. Begin with the letters RT. Don't waste valuable characters (you've only got 140) with preambles such as "Retweet."
2. Give credit to the source of the tweet by using @author, where "author" is the Twitter username of the person you are referencing. Sometimes there will be multiple names attached because it's been passed along so many times; make sure you are keeping the original source if you trim the chain of users.
3. When linking to something, shorten the URL you are referencing through a tool such as http://ow.ly or http://is.gd.
4. Use the remaining characters to explain the point of view or the link in the original tweet, preserving the spirit of what the source said.
5. Think twice before retweeting sensitive material or information that may be untrue. You don't want to embarrass people or spread lies.
6. Think about whether what you retweet will have relevance to any of your followers before posting. And avoid spam -- it's all over the Web.



