i think it's a cool sound but i wouldn't mind shutting it off either. I like as little noise as possible coming from my blackberry, including key clicks, tones, etc, etc...
I know some phones make that sound every time you make an outgoing call. I had a friend who had a phone like that. I don't like it, but i can deal with it for speed dials. :p
ok, ok-- i love that sound.
And no, unfortunately there doesn't seem to be a way to shut it off that I've found. I've tried everything.