Using vB's sessions in Wordpress and Mediawiki

[curry684]

After about a day scouting through the various existing topics I decided to open up a new topic because none of the topics seem to cover my situation, and as I'm new to vBulletin I simply don't know enough of the subject yet to hack my way through. Also, I want to do it right the first time.

Situation:
- News section is running Wordpress 1.5.2
- Wiki section is running Mediawiki 1.5.4
- Forum is running vBulletin 3.5.3

News and Wiki are in full production but without user registrations enabled (anon comments and edits), because I wanted to wait with that until I could integrate it with a forum. Now I've purchased vB and it's completely set up, and I'm only left with the integration problem: I don't want to have users log in at 3 sites separately.

So, all 3 sites are running on the same server (and will be for the foreseeable future) and are underneath the same domain (subdomains www., wiki. and forum. respectively). I will be adding custom code in the future for specialized community elements.

My first idea was to make a central user DB myself and then sync this to the 3 other databases. Since I've taken vB for a test drive though I think that using its registration system makes more sense, and then sync it from there to Wiki and Wordpress that have quite thin registration systems.

But how I am going to do that syncing, and worst of all make sure that a forum login works for Wiki and Wordpress, I have no idea. I'm an experienced programmer, but I just don't know where to start and what approach would be best.

Anyone got some pointers?