Rattle/vibration noise

[sc0ttie]

The past couple of weeks my 99 fzs600 has had a bit of a rattle occuring, it seems a bit more obvious when cold but also it can sound like a vibration. I took a video of the bike being revved just now, this was after a 20 minute ride, so it sounds more vibey than rattly but you can definitely hear it best toward the end of the vid.
I am not sure what it is but could this be my camchain being loose?


http://www.youtube.com/watch?v=8m62fzfYo68