Just to stretch the envelope a little further before the balloon bursts ...
Here's a simple workflow shopping basket scenario that might use a combination
of cookies and hidden fields to accomplish a single complex ordering transaction.
Company A and B sign up for a collaborative project. Each compnay
will need to purchase some software and hardware from 2 or 3 vendors
to get the project started. Let's assume that they share a secure
means of transferring email and that they both have web enabled
mail applications on their desktops.
The project manager A.mgr1 constructs a document to cover the first
proposed purchases. The first additions to the document are for
the company B manager (B.mgr1) and company A's engineer (A.eng1).
As the document is wrapped up A.mgr1 clicks on the link which forwards
the contents of the document to A.engr1 like a routine slip.
Several links are added to the page for various vendors products
(C.prod1 D.prod2). Some products were linked in with special
deals (C.prod2.reserved.1.2345 at C.prod2.promotion.price
valid til C.prod2.promotion.end_date).
When the engineer finished with the proposal, it was dutifully
forwarded to B.mgr1 who repeats the process with B.engr1. Some
of the items were simply copied so that both companies would
be using the exact same products (except the prices were slightly
different due to the timing of the orders and the local
supplier ordering policies (e.g. $, ¥, £).
After the final approval process, A.mgr1 and B.mgr1 make the final edits
to the documents and each issue the purchase order for their
relevant products.
This scenario would require some amount of state to be transported
along with the document. Information identifying the various companies,
departments and employees would need to be maintained in a secure
way. Some of the state would be stored at the vendor servers to keep track
of reserved products or special pricing. Some state would be kept on
a clients workstation to keep track of document routing and intermediate
results of the larger transaction in progress.