The sources of the SimGrid 101 presentation are in the propagenda
section. The script to generate the pngs from the pdf are on Martin's
hard disk only (sorry). Here are the interesting bits of it:

error=0
for n in `seq 0 $NUM` ; do
 if [ x$n != x$NUM ] ; then # lame. should iterate over [0,NUM-1] the  proper way
   m=`expr $n + 1`
   echo -n "Page $m of $NUM... ";
   file=${PNGDIR}_`printf %03d $m`.png
   if [ ! -e $file ] || [ $file -ot ${PDF} ] ; then
     convert -density 400% "${PDF}[$n]" -resize 30% $file || error=1 
     echo "converted"
   else
     echo "kept previous version"
   fi
 fi
done