I did eventually get my camera to work with Linux. As I mentioned before my cheap Mustek MDC 3500 didn't work as simply as I hoped under Linux, but because it supports USB mass storage it ‘just worked’ under Windows. Turns out that the reason it didn't work under Linux was that my kernel was missing the relevant entry in a table of recognised USB devices.
It looks like this Polish webpage is giving the appropriate table entries, which can be added to drivers/usb/storage/unusual_devs.h to get this working. I haven't tried that, but I did upgrade to Linux 2.6.0, which has these entries in. Now it just works. I can mount the camera filesystem with the following /etc/fstab entry:
/dev/sda1 /mnt/camera vfat defaults,user 0 0
I still haven't been able to point gphoto2 or anything at my camera. They have the same problem with incomplete tables of USB devices. It seems a bit daft having the kernel and each camera application having to know about every camera model. But at least I can mount the thing and take photos off it.
So here's a badly taken photo of a squirrel in next door's garden (unfortunately I missed the moment when it was sitting on a branch staring at me):
Backup device?
I thought that since I had the camera plugged in just now I might as well find out whether the filesystem Linux talks to is really there and not just a fake view on the internal data. It seems to be ‘real’, in the sense that I can copy arbitrary things to it. I've used it to make a backup of my CVS repository and this blog.
I expect big corporations and military types are upsetting themselves about the espionage possibilities of this stuff. Ordinary people can now wonder around with ¼Gb of storage on a key-ring. Much niftier than the old MacGyver-stylee microfilm-in-a-watch trick.