How can I rename photos, given the EXIF data?
Just found out here that jhead can do it all for you! :)
jhead -autorot -nf%Y-%m-%d_%H-%M-%S *.jpg
You can to it for all files using a for loop (in the shell/in a shell-script):
for i in *.JPG; do
j=`jhead "$i" | grep date | sed 's/^File date[^:]\+: \(.\+\)$/\1/'`.jpg
echo mv -i "$i" "$j"
done
This is just a very basic outline. Delete echo
when you have verified that everything works as expected.