If your services talk only XML, i.e. return XML documents containing data, then the connection between catalog to basket is not necessary.
would return something like this:
And would accept putting any resource into it, e.g. http://site.com/basket/Louis?http://site.com/catalog/car
Such services are easy to implement, no connections are necessary between them and they are reusable from a third party app.
Now you only need GUI to use them. If you build GUI on the top of the same URLs then of course you will need to link from one to another. But your GUI may be a completely different URL where you simply use these 2 services.
[ July 08, 2008: Message edited by: Vilmantas Baranauskas ]