[Image-SIG] Copying EXIF data from one file or PIL image to another?

[Terry Carroll]

Can anyone tell me if it's fairly easy to copy a JPEG file's EXIF data to 
another file.  Even better would be if this is doable in PIL.

My basic problem:

I've written a small program that reads a JPEG image in PIL, and creates a
copy that is slightly modified (it overlays the image with a datestamp
taken from the EXIF data), and saves it as a new file.  It all works
swimmingly well, except that the ne file has no EXIF data.  I'd like to 
copy the original image's EXIF data to the new image.