$ sudo apt-get install gphoto2
Once it's installed, navigate to the directory you want the photos extracted to and issue this command:
$ gphoto2 --port=usb -R -P
If you want to extract a known range of photos, do this:
$ gphoto2 --port=usb: -R -p x-y
where x is the starting photo number and y is the ending photo number. Easy!