A way to forward users to other websites - transparently

Is anyone here, aware of any existing HTML
code or package that will forward the user to
one of 5-10 other web sites, in a transparent
fashion, keeping track of who was sent where?

The application is a popular single word domain,
such as www.tires.com. users that go there,
would be sent to one of 5-10 different tire outlets,
who would be then be charged per user that
was transferred to their site from tires.com.

I can't be the first one that has a need for this.
Is there a common name for this type of
application, or a plug and play HTML package
that is for sale that does this type of thing?

Thanks for your helpful reply.