Just making a note to myself for when I want to make a high resolution geo-referenced map composed of different input data layers. As described here, one can save an image of the current map(s) in QGIS, but the image will have a fairly low resolution (it is basically a screen shot). You can create very nice maps with the ‘print composer’, but then it will not be geo-referenced.
A solution is to use the QGIS command line to create a snapshot of a map. This way, you can create images of any size and with corresponding world file. See http://underdark.wordpress.com/2010/11/30/creating-high-resolution-images-using-qgis/ for a step by step description how to do this.