I've used doodles and icons in note-taking for years, the goal was to document my emotions/reaction to a presentation/sermon/seminar which helped me recall finer points later. I sketch exclusively in color. Then there's a similar tool called mind-mapping which is not necessarily about note taking. Take SKETCHNOTE as far as you can. I checked out the flickr SXSW page and was amazed at the volume of data you captured. All the best.