GRASS vector export to Inkscape
Inkscape Inkscape is a free vector graphics program. The native data format is 'svg' which means 'scaleable vector graphics'. The only problem is that there is no direct svg export module in GRASS. But there is a shapefile to svg converter shp2svg converter.
Inkscape uses a coordinate system which represents the final map output (i.e. 210mm x 297mm for A4). Therefore a scaling of the geographic coordinate system is needed. I've get good results from a lat/long region with the following command:
ogis2svg.exe --input yourinputShapeFile --output youroutputfile.svg --roundval 0.00001 --scale 0.01
If you wan't to import several files into Inkscape you'll have to place them all at the same place. To do use the XML-Editor from Inkscape (View->XML Editor) and check for you imported object that the transformation is the same for all object (for example: 'transform translate(-7400,1850)')
A sample file can be found here: Inkscape demo map