Wouldn’t it be nice if you and your readers had the option of placing events in a shared calendar. Let say you have a political or music blog and you’re writing about meetings or concerts. You might want to add a date to your WordPress agenda. These events would then be added to a Event Calender page on your webblog with the date and time and a link to the post.
A registered user or a user with a certain level or role, should have a tab in the admin section which says Agenda. Even better would be an upload option in a post & page where you can upload an event on a specific date, select the events category and add some text and links maybe an image (e.g. automatically resized to avatar size 80 px x 80 px). In the end he post it onto the front-page and it also shows up in the weblog agenda.
Visitors of the website can browse though the agenda by date and category. Registered users see a link where they can add a agenda event themselves. There should be a distinction between old agenda events and events on future dates.
Very nice adds would be if visitors can e-mail an event to a friend, registered can notify other users that they will attend this event (like you can do at upcoming), visitors and users can comment on an event, everybody can social bookmark the event (e.g. on digg, delicious).
An other nice feature would be a sidebar widget which shows today’s and agenda’s events placed on the weblog’s agenda page.
Future plugin’s could add extra features like Placer / Google map functions so you can add a map to the event.
Curent plugins do not have all the above options. It would be very nice if it was a standard page (like Archives) in WordPress.
Also read: http://wordpress.org/support/topic/93569