There have been several new “blank canvas” Mac apps released recently. The main three are Scapple (A+), Delineato Pro (A-) and Mindix (still in early development). These programs are not mind mapping ones. They are very simple ways of cutting and pasting snippets, links, pictures, paragraphs and other information onto a large canvas or sheet of paper like those we used to decorate the walls during meetings.
The mind map below shows features of the various blank canvas apps.
Scapple and Delineato are both highly recommended.
ADDITION March 2, 2014: Big Hairy Goal has recently been released for the Mac and is comparable to Mindix but much more highly developed. I consider Big Hairy Goal worth rating A.