User profiling within my web site

i dont know if this is the right place to post this but if any body could give me somehelp either in this subject or where to find info about it. I want to create a web site that incorporates user profiling , e.g. a site that changes to the persons prefrence.
Thanks

What type of changes are you talking about?

I think that a lot of companies think this is the *cool* thing to do, but they neglect to ask themselves one important question...

1) Is our user really going to take the time to customize the colours?

I guess this really depends on the type of site you're dealing with... but it's definately an issue worth looking into... even the most popular user-customization sites of the past have somewhat limited their functionality on recent redesigns... I figure most likely because allowing such customization was a waste of their own time and money...

Depending on the scope of your site, you might want to look into a Portal solution... but some come at high costs...