vlingo - speech to text. Not sure if you have to ring a number, it seems more like, hold the key, speak, and then send…also updates Facebook Status. Also see Twitwoop, TwitterFone, Twitsay, Jott, Spinvox [via m]
Poll Everywhere + Twitter - A polling form where the audience can tweet their answer, and the widget embedded into your blog, website or online doc will display the current progress…great for live audience presentations (using Twitter in PowerPoint)
Mixero - A client that has some great features - create groups, channels, and filtering. If you ask me Filttr already does all this - filter slide for tweeps, black/white list words, create groups, create keyword streams, it also has automatic filtering based on your past behaviour, and a mobile version. My favourite filter is creating a group, then filtering that with a a few keywords, and then filtering that again to just show me tweets that have links in them.
For other filtering sites see peoplebrowsr, TweetGrid, Monittor, ConvoMonitor, JustSignal, Twalala, microplaza, and Ginx. [via RWW]