Some Success! If your iPhone is still in recovery mode and you have
NOT restored this may work.
I have a friend with an iPhone, at some point yesterday her phone was kicked into recovery mode by a failed update or something. She like others had images that could not be replaced so she was going to hold out as long as she had to before doing a restore. She contacted me I googled around hoping to find a way to gain shell access and see if I could copy the images via the command line and I found an application called iNdependence.
http://code.google.com/p/independence/
I installed iNdependence as per the instructions that come with it. Then launched iNdependence and turned on the phone which was already connected. Then I clicked the SSH tab in iNdependence and without ever even getting into a shell the phone left recovery mode and went to the normal home screen. I have given her the phone back and she is going to try and sync her files after she emails all of them to herself as a safety measure. To be honest I'm not sure how it did it or if will work for others but it's worth a shot.
System info:
iPhone firmware 1.1.1
iTunes 7.4.2
Mac OS 10.4.10
iNdependence 1.3b2
However if you have already restored your phone your chances of recovery are very slim as I believe the memory gets wiped as part of the restore process . Short of having the phone taken apart so the flash memory can be accessed directly without the OS in the way and even then chances are slim.
Good Luck