Yes i can.

One thing i did not mention yet is that i use standard USB cables.
So NO OTG enabled cables.

For a single shot on my Nikon D40 the script would be :

echo host > /sys/devices/platform/musb_hdrc/mode
sleep 1
/usr/local/bin/gphoto2 --set-config /main/settings/capturetarget 1
/usr/local/bin/gphoto2 --capture-image
echo otg > /sys/devices/platform/musb_hdrc/mode
sleep 1

the only little annoyance i have now is that gphoto2 spends a long time initialising before it actually takes the picture.