Write rotations to disk?

[David Barrett <dbarrett quinthar com>]

I just went through all my photos and rotated them correctly, only to 
realize that the rotations are not written back out to disk -- if I load 
one of the rotated images with Firefox (or, more specifically, with 
Desktop Drapes), it doesn't appear rotated.  Oops!  With this in mind, 
two question:

1) Can I configure F-Spot such that when I rotate an image, it actually 
writes the rotated image back out to disk?

2) Can I instruct F-Spot to go back through all the images I rotated and 
write them back out to disk in rotated form?

Oh, and I guess one more question:

3) Know of any way to configure Desktop Drapes to detect the F-Spot 
rotation information that I assume is written into the file's metadata?

Thanks!

-david