Fully integrated authentication for a site

[thetadpole]

Hi,

I'm looking at buying a copy of vB for a web site I'm working on. The site is going to be very heavily community-based and personalised for each user. It will show listings for events that a particular user might be interested in, it will e-mail them listings on a weekly basis and it will help those who have similar interests meet each other and chat on the message boards.

I'm already a quite experienced PHP programmer and am building the listings engine and related stuff from scratch - I can create separate tables storing members' music/event preferences and cross-reference that with their memberID in the mySQL table, if that's the way that vB stores it. My question is - how easy is it to integrate the authentication system and cookies used by vB with the rest of my site?

If you could take a look for example at http://www.harderfaster.net/ which uses vB - links to your user cp and your current username are always at the top of the page, and when you are logged in, you see your PMs on the home page, and you can do things like post comments on articles and features within the site, because it recognises your login. I'd like to be able to do something similar, and do further things like add on links to who's online from a member's Buddy List on their home page, events they recently viewed, events which feature a certain band or DJ they like, or maybe a calendar of events they've said they might be going to (so other members can then also see who's going to be at the same event with them).

The site above seems very much like what I'm intending to do. I don't want a "portal" per se; I don't really need CMS, as I'm not going to have hundreds of thousands of articles or news items that I need to keep track of. Instead I'd just like to be able to offer users personalisation on various sections throughout the site, based on one single login - their forum login (although this won't be titled as such, it will simply be like registering to be a member of the site, except the backend for keeping the list of users/passwords is vB). If possible I'd also like to be able to restrict certain areas of the site to members only.

Can this be done? I know with phpBB that it can - I can get the user's details through the phpBB cookie.

When all said and done, HarderFaster seems like a site which I'd very much like mine to be similar to (in terms of community, but far different in terms of content and features). If someone could just give me any clues on how HarderFaster have done their site (maybe the querystring URLs are a dead giveaway to some particular bit of software they've used) then I'd appreciate it.

Thanks.