I'm not sure how tough this is, but I've seen several sites that are doing something similar. I'd like to allow members to login from my main page (not the forums area), using the same ID and password they use for my vBulletin. I'd then like to offer a subscription service that keeps them from having to see any of the ads on my site.

The login wouldn't have to be mandatory, I'd just have something like "Welcome, Unregistered" (or the user's name if they're logged in) like vBulletin does on its main page. Once logged in, if the user has paid a subscription fee, a cookie would keep my banner and popbehind code from loading.

What would be really nice is to be able to go into the admin area of vBulletin and just update user IDs as people paid the subscription, changing them from "Registered" to "Paid Registered" or something.

you'll find that most subscription processors have a payment notification service, i know paypal does.

I just finished a hack for a client which allows users to pay the selected amount and then they are moved into a paid usergroup. If the subscription is cancelled or its end of term they are moved back into the registered usergroup.

I'm guessing you have no knowledge of php code, maybe someone can create a hack like this for you.