i got this too also when i am holding my phone in my hand. i think some way we are pressing the "return", "menu", "home", and "search" buttons the bottom of the phone. they are very, very sensitive
It's a hardware issue.
I pulled the battery - no help.
Then I did the unthinkable - after so many hours of setting this up I did a full reset of the Droid....
But I did use an application called MyBackup - GET IT.
Nothing cured the clicking.
We even brought it other locations.
I'm going to exchange it tomorrow - hopefully I won't get one with other problems.
But MyBackup get most of your stuff up and running very easily. 30 days free. I may buy it. Just $5 is worth it.