Guys, this has bugged me for a while, but seems to have gotton worse now.

I have a metallic sounding rattle/knocking on my car. Its noticable when:
- I first start up (but that could be linked to the next point)
- I blip the throttle slightly (800 -> 1200 rpm)
- When I go over a bump in the road.
Any ideas? Someone once said its the middle exhaust bracket. Is this correct?

What choices do I have? Also, what else could it be? Really starting to bug me.
