Twitter has announced major changes that will alter the way the company calculates 140 characters. Certain attachments, URLs, and handles will no longer count towards the character limit. Changes will allow users to use more words, and developers must prepare for the upcoming changes.
At the bottom of many blog posts (including this one) and website entries you're likely to find a widget that allows sharing to social sites or emailing to a friend. ShareThis competes with other systems like AddThis and SocialTwist to give publishers an easy-to-install sharing method.