I have an early 2008 MBP, 15", 2.4 GHz, etc...it's on its 2nd month out of the box... Anyways, I was on youtube last night in bed and notice that there's a vibrating/rubbing sound coming from it. Usually all I hear is the gentle "whir" of fans spinning, so this new sound was pretty noticeable. I put my ear closer to the keyboard and found that the sound is coming from the right side, between the "enter" button of the keyboard and the screen. I'm thinking it's either the HD or the fans on that side rubbing/hacking away on its setting. Has anyone else experienced this? Will it go away on its own or should I be making an appointment with a Genius?