As Twitter keeps growing, bad people are trying to hack it, programmers are developing new features and applications and marketers are creating new niches. No need to talk any more about this week’s twitter virus and today’s Steve Jobs’ fake gossip (it came from MacRumors). Twitter needs a groups feature, so that things like Twittermoms or GospelR can be done on its site.

It’s clear that users need a way to divide their followers and marketers need a way to address messages to certain groups. Having a single flow of messages is good as a start point but will not grow to convert Twitter into a complete social network. Company twitter-like tool Yammer is doing it so much better!

Half a year ago Twitter admitted it was working on a groups feature, but there had not been any news so far, but a small test in Japan. Meanwhile, people have created small applications, such as Twitter Groups, Twittbot or GroupTweet (I especially like this one).