After long hours of hard work we recently released a beta version of our web appliacition ClickOnEvent.com. It is a service dedicated to event management. You can publish events accept participants, create a custom on line registration form, accept tranfer reservations, accept accommodation reservations, have different fees on your events, accept payment, create custom portals for your events etc.
The application is completly based on dotnetnuke. We haven't tuched the core so it is still upgradable to new versions of dnn.
Come try it out! It is free. We will be glad to recieve any feedback. You can find the appliacation on beta.clickonevent.com
Thanks for your help!