When I shake my MacBook Pro it makes a strange noise. I have bought brand new MacBook pro 15-inch model with highest specifications in this June. I have also installed newest Mac OS, Lion.

Now I have a small problem (or maybe not) here. I would like to ask you what could be possible wrong that when I shake my MacBook Pro it makes a strange noise? Maybe it is just the noise of the keys on the keyboard?
The only thing I can think of that would be shaking is a loose screw.  I'd recommend taking it to an Authorized Apple Service Provider to have them poke around and see if they can get it out.  If you are daring enough (or out of warranty), you might want to try it yourself.