Yup, that is the exact noise that I had. At lease Ford is fixing them now. For a while Ford was telling the dealers to tell customers that it won't do any harm so don't worry about it. Then they finally released a TSB saying that 'persistant' customers should have the cam phaser fix done. The first fix they had out didn't work for most people, then in May of 05 they finally came out with a fix that works. Don't let them give you the old 'it's normal' routine.
If you have any more questions about it just go to F150online.com, go to the 2004-2006 body style section and search for cam phaser, lots of info. It sounds identicle to what mine sounded like.