Explain Everything - Explain Everything is an easy-to-use design, screencasting, and interactive whiteboard tool that...

Xmind - Xmind is a brainstorming and mind mapping application.

Conceptboard - Instant Whiteboards for Teams & Projects

MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.

Microsoft Whiteboard - The canvas where ideas, content, & people come together.

FeatureMap - FeatureMap story mapping, simple and effective realtime collaboration and collective intelligence tool.