asp.net save to outlook calendar

Require the development of an asp.net / vb.net page to take input of a date, subject and description and then when 'submit' button is pressed, it will insert it as a calendar item on the local users outlook (must support outlook 2003 and outlook 2007) It would be preferable to generate a file that when opened from the browser, it creates the calendar item. Alternatively, we will accept an email of a calendar item that can be 'accepted' to go into the calendar.