Attached is a basic example of how you can integrate/mash onDemand into Microsoft Excel using Visual Basic for Applications VBA.  Allowing you to access the rich functionality of Excel or integrate in an existing Excel based system.

The example logs you on, displays your firstname and allows you to send a basis message (email).

Some use cases:
# Getting xml stream and creating data for range for use in reporting graphing
# Getting user data and sending back to mydigitalspace eg sales order.
# Sending a message based on user input or calculations of user input

There are notes inside the attached xlsm (Excel with Macros format)

Again this is just example code and would need work to be used in a production environment.