This could be a RTFM type of question 
but how do I link up two or more track volumes with each other so that I may raise or lower their respected volume settings together at the same time?
not possible yet, I think … But a solution is to send those tracks to a sendtrack and set the volume there.
Doh! Wasnt fast enough replying 
Oh well…
As said by looza… The easiest way I can think of right now is to use send devices and send the tracks of choice to one send track. Though they will be mixed together in the end but maybe it is not a problem at all. Anyway then the volume-bar on the send track will control the volume of the mixed tracks.
Yep, I should have figured that as I’ve been trying to use the send tracks for certain effects lately. That’s easy enough… Thanks people!