I posted a question about integrating this over at vB.com:
http://www.vbulletin.com/forum/showthread.php?t=140646
I already posted about this in the first page of this post, but that was over a year ago (and the instructions for how to do it lost me) -- does anyone have any new tips/ideas?
As I said there, the only idea I have is to change all the user IDs of members of my gallery to some really high numbers, and then go back and change them to IDs that match their IDs at the board, but I guess that might be a problem if I'd have to change that on each user's pictures as well if pictures associate with the ID and not username or something.