In this screencast, we’re talking about five Twitter tools that help you manage your feeds and update multiple networks, schedule tweets, advertise, and one that acts like a directory.
Hellotxt.com
Grouptweet.com
Wefollow.com
Twuffer.com
be-a-magpie.com

Comments
Add TweetTwain too, one of the best tool I have ever seen on internet for Twitter marketing.
we really like http://followerwonk.com/ to analyse user bios and user groups. quite efficient.