Mind maps are an effective way to gather information quickly and organization those ideas. For software testing they provide a great tool to share test plans with product owners and testers in an easy to comprehend manner. The visual clarity of mind maps display content in a usable manner.
Hexawise allows you to import and export mind maps. So you can brainstorm ideas together (users, business analysts, product owners, testers, managers...) and agree on the important items to test. And then you can import the mind map into Hexawise and it will generate an optimized test plan with efficient combinatorial coverage (enhanced pairwise testing to test the performance of the software interactions between parameters and parameter values).
You can even use mind maps to edit and maintain your test plans: see Hexawise training explanation of how to use the editable mind maps to edit your plan.
Image of the edit screen for the mind map for an airplane ticket reservation system (the first Hexawise sample plan - you can view the plan in your Hexawise account and experiment with the mind map feature).