producing this model:

• apt-get install gdal
• apt-get install python-gdal
• sudo apt-get install png23d
• grab srtm data and unzip it (cd srtm && wget http://dds.cr.usgs.gov/srtm/version2_1/SRTM1/Region_01/N45W122.hgt.zip)
• fill in data gaps -- gdal_fillnodata.py src dst
• build an image with gdal -- gdaldem color-relief srtm/N45W122.hgt monday/colormap.txt hood.tiff
• crop it a little (just to hood), save as PNG
• png23d -v -t x -f surface -o stl -l 128 -d 90 -w 200 -h 200 hood-filled-cropped.png hood-filled-cropped-l128-d90-w200-h200.stl
• export an x3g in makerware