I would like to ask if somebody could advise me how to create an "Attend" button in the Event form which appears when clicking on an Event. The goal is that there is a list of participants visible under each Event? And also I would like to add to the same one single window under each Event a simple discussion without a need to create an Event Workspace with a discussion there.
Then you'd be able to put a data view web part on the page which has a query string parameter filter that looks at the ID to filter the items from the registration list, showing the created by person.
I'm not entirely sure if the same sort of thing would work for discussion boards or not. We rarely use them.
You can create a multi user column called "Attendees".
Then you can create a custom display form, that has an attend button, which appends the SPUser object of the current logged in user, from the SPContext object to this column.