I hear the "clicking" your talking about, and her is how I get it to repeat:
Open the MBP so the screen is 90 degrees (=/-) open and put the laptop on your bed, or any soft/non uniform surface. Now use one finger/thumb under each of the front corners and lift up, only takes an inch or two, and rock it back and forth. To me it's the bottom cover flexing and popping, not the HDD as the sound comes from different locations. Right, left, front, back etc.. or so it seems anyhow..
I guess I should pay closer attention if it is coming from where the HDD is located
After looking for a teardown, if I'm looking at it correctly the HDD is under the left side wrist area? The clicking I am hearing more often then not is very clearly on the right side.
Ok so the HDD is likely what's going on. I close the lid and the computer sleeps, which likely locks down the HDD... and I no longer have the ticking no matter what I do lol. Sheesh, sometimes the obvoius is right there, oh well happy it's a "suppose to hear clicking" vs a "what the hell is that?" lol