Xmind - Xmind is a brainstorming and mind mapping application.
Framadate - Make your polls
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.
FeatureMap - FeatureMap story mapping, simple and effective realtime collaboration and collective intelligence tool.
Dudle - Dudle is an online scheduling application, which is free and open source.