Hello Chris!

> Wonder if anyone can help me here. I'm trying to create an image file from
> a USB storage device which is held on a cheap camera. The problem is that I
> want to create this image (with dd - eg. dd if=sda of=image;sync) without
> altering any data on the USB device. I am hoping to use the md5sum command
> to verify both the image and the USB storage device. Am I right in thinking
> that no changes will be made aslong as I do not mount the USB device
> directly (eg mount -t etc...)?

I would say so. As long as you do not do 'of=/dev/sda' ofcause.
I am not sure you can get the same output from md5sum when using dd. dd
read blocks and what if the data do not end on the same block boundary?
Hmm anyone? Maybe a "cat /dev/sda > myimage.dat" would do the trick. It
would be easy for you to test.