Sharing
 

I am opening a new site and it coincides with the forums I have running already. Is there anyway for me to share the user part of the db with the new site so my old forum members do not have to register again on the new forum? They have asked me this so I am asking the experts.

search for a converter script from your board to vbulletin. There are many covnerters around for different boards.. If none exists you have to code it one..

No. You are totally missing what I want to do.
I have a vB on one site. Yet I am getting another vB and opening a related site that will be on the same server. I want to have it so my members at site one can be members of site without registering.

download the user table and the profilefieldtable and upload to the new server per phpmyadmin

instead of using the entire "user" table, I suggest writing a script to read relevant data from one of them and insert it to the other..

If you upload the entire user table, there will be some clashes in the new board, such as post numbers. But if your new board has no users yet, uses the exact styles with the first one, have same user groups, coppa settings, user titles, you can apply Xenon's suggection and then run some SQL commands to reset post numbers, join date, last visit, last activity, last post fields..

Great thanks guys. Now to write it!