NineChime forum

So I have a punbb message board that I use along side my wacintaki oekaki board, and I was trying to think of a simple way to integrate them. From what I understand, the real problem with integration comes with different encryption techniques,  the need to combine the user tables in the database, and having both share the same cookies. I don't think I need all of these features, but I would like a way for a user to register for both the oekaki and the forum at the same time, this way they don't have to wait for two confirmation emails and whatnot; it doesn't really make a difference if they have to sign in twice per session..

So what I was thinking was using some sort of separate registration script that takes the users username, password, etc. and inserts it into both of the database tables at the same time. For example, a user would put in their desired username and the script would send this information to both the forum and oekaki tables in the database, as if they were signing up for each individually. This way, the password could be inserted, encrypted one way and sent to the oekaki table, and encrypted another for the forum table. (The registration form would only really need places for username, password, and email address since, after they log in, they can edit specific fields (such as interests, aim screenname, etc) afterward.

I really have no idea how this could be accomplished since I am an extreme beginner at both php and mysql; I was just wondering if this could be accomplished. (And if anyone could look into writing a form like this for me; I'm sure it could come in handy to other people as well since it probably wouldn't be too difficult to change for it to work with another forum or gallery script.)

Thanks!