Learning Biztalk 2004 and 2006

I've made a conscious commitment to learn and improvise my Biztalk Server Skills.

I'll be posting and making journal entries about the progress I make in the Biztalk Server Concepts.

When I refer to BizTalk Server, I mean Biztalk Server 2004 and 2006. I'll mention the version names when there is a discrepanicies in the features between 2004 and 2006.

I would Like to start the Discussion about Biztalk by jotting down in what scenarios I would use Biztalk. (this is not an extensive list of biztalk scenarios but I intend to add to it in the future.) :

1. Changing Business Rules. (A rule defines how the tasks involved in the business process are performed.)
2. transfer business data (using adapter and accelerators.)
3. connecting disparate enterprise applications using rules or publish and subscribe (centralised integration service).
4. Structuring Business Processes using HUB - BUS Model .
5. Optimise the Business Processes using centralised state container and Orchestrations, BAM.