rsync to multiple destinations

[Johan Kröckel]

I am looking for a way to start one rsync command with multiple destinations.
My use case:
I have one (slow) usb drive which should be synced to two other
harddrives. It would be great if rsync could read one file which is to
be copied to both hard drives only once, so the slow usb connection is
used more efficiently.

Any idea or is this a wishlist "bug"?

Thanks