For those who have been under a rock (or haven't been?), the trick here is to find the node in a busy server/zone, mine it and the log off and hope you log back into a different overflow or into the main zone and then mine it again.
That being said, how about a thread listing locations?
Here is mine:
This is Iron in Gendarran Fields (25-35), there are NO tough mobs (veteran, champion) that you have to go through to get here, nor is there anything that will spawn on top of you while you're trying to mine it.
(!empty($user->lang['ATTACHMENT'])) ? $user->lang['ATTACHMENT'] : ucwords(strtolower(str_replace('_', ' ', 'ATTACHMENT'))):
Gw2 2012-09-17 09-17-17-34.jpg
(!empty($user->lang['ATTACHMENT'])) ? $user->lang['ATTACHMENT'] : ucwords(strtolower(str_replace('_', ' ', 'ATTACHMENT'))):
Gw2 2012-09-17 09-17-10-60.jpg
(!empty($user->lang['ATTACHMENT'])) ? $user->lang['ATTACHMENT'] : ucwords(strtolower(str_replace('_', ' ', 'ATTACHMENT'))):
Gw2 2012-09-17 09-17-59-57.jpg