Idealist - Volunteer, work, and intern job search
Xmind - Xmind is a brainstorming and mind mapping application.
Nugget - Find your perfect startup idea
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Idea Hunt - Solve specific challenges for your favorite products
MindManager - With MindManager, flexible mind maps promote freeform thinking and quick organization of ideas, so creativity and productivity can live in harmony.