Multiple website - single sign-on

[Easific]

Its a can-I-do-this question.

Suppose I have multiple websites all running vbulletin. Can I keep a single sign-on and registration database between them?

If a user registers on site A.com, he automatically appears in sites B.com and C.com. Common user database.

When he logins to B.com, he does not need to login to A.com and C.com when he visits them. Something like a common cookie.

[Brandon Sheley]

yes, it can be done
pls don't pm me asking how, but I know it has been done, sites like www.crowdgather.com are doing it on 100's of forums

[Easific]

Haha.. I am not the type who would hassle people on PM. Glad to know it can be done.

Now if only someone could point me in the right direction.