TwitterFeed
Twitterfeed use your RSS feed to post directly to twitter, identi.
6 Alternatives To TwitterFeed
Engator
Engator (your RSS to Twitter, RSS to Facebook service) enables you to auto-update your social networking sites like- Twitter, Facebook and Linkedin from one central platform.
SocialScud
SocialScud is a Social Media management platform to help drive social media results.
Swift Social
All-in-One Social Media Growth and Management Tool