"Locking" a machine to locations

[Tara Calishain]

Gentle Librarians,

I've been asked to assist in securing a computer that will be connected to 
the Internet.
The people concerned wish to limit the Web access very drastically.

Basically they want to limit Web access to one or two domains AT MOST. One of
the domains will be a standard domain, like www.news.com, while another 
will be a
subdomain, like dailynews.yahoo.com .

I have seen discussion of this in this group before, but I don't know if 
the narrowness
of the scope is a problem. Has anyone done anything like this? Is there 
software you
would care to recommend?

thanks,

Tara