iPod Photo Liberator Mac & Windows: It's website does not exist anymore
iPodCopy Mac and Windows Versions:
http://www.wideanglesoftware.com/ipodcopy/
The demo version I tried succesfully in transfering 21 photos directly into iPhoto.
Keith's iPod Photo Reader:
http://www.cs.unm.edu/~kwiley/software/keithsIPodPhotoReader.html
I managed to transfer all my 750 photos onto my computer in the Apple PICT format. This files can easily be imported into iPhoto.
In both cases I could only save the photos in the quite low resolution of 720x480. This may be the size the iPod uses to display photos. If someone wants to save the photos on the iPod in full format he should enable the in the iTunes settings the option "including the photos in full resolution" (this is my translation of the option in my german iTunes, "Einschliesslich Fotos in voller Auflösung").