I just posted a quick tutorial on 'How to Make a Nice SVG Map with Gimp and Inkscape (the Quick and Easy Way)'

It basically uses Gimp to generate a topographic terrain map,and Inkscape to turn that rastor graphic into an SVG for use in video games, on the web, and are great for Print and Play (PnP) games or additional maps for your favorite board games.

tutorial: http://simplemediagroup.net/?p=423