Spider-diagram unlimited canvas

I currently document my thoughts on this blog and in a collection of text documents and spreadsheets. What I want is a unlimited canvas, similar to a presentation editor (e.g. Powerpoint) with the ability to put in textboxes (with as much functionality as something like Word), spreadsheets (with as much functionality as something like Excel), pictures, etc and have all of these linked with labelled arrows showing the web of my thoughts.