Login to vB on an EXTERNAL domain (forums on domain 1, site on domain 2)?

[wsdeluxe]

Hi,

I've been trauling through the billions of threads here regarding external login however none of them cover multiple domains.

Heres my situation:

I have 4 domains, with the forum running on one of them. (site1.com, site2.com, site3.com and forums.com)

I want to be able to login on each individual site. All the sites share 1 database and 1 server. I already know that its not possible to use cookies, and I already know the modifications for external logins only work when you are using 1 domain.

The only way I can see that this can be done is by either somehow setting cookies for each domain, or have a custom login for each of the sites.

Can anyone suggest how this can be done? I know its possible, it just seems that nobody has covered it.

To save you some time, I'm not a newb...I've been using vB for a good few years and have good programming skills. I just cant seem to get this one working though.

Any help would be appreciated.

Thanks