Quite often I find myself in a situation where I need to explain hardware or software GIS infrastructure to people with no or limited knowledge of GIS. Or give an overview of geoprocessing tasks involved in an analysis.
In such cases picture can be trully worth thousand words. Doing last minute preparations I usually relied on quick and dirty PowerPoint slide with random assortment of free icons and images from around the web but I would be more happy to invest little bit more time into something that will look better.
I'm thinking about schemas resembling for instance images like this:
What kind of software (preferably free) would be best suited to create such images?
Is there any place where you could get (preferably for free) 'GIS-specific' icons used in such diagrams?